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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   FORM 10-K


(Mark One)
(X)               Annual Report Pursuant to Section 13 or 15(d) of the
                               Securities Exchange Act of 1934

                  For the fiscal year ended December 31, 1999
                                             or
( )               Transition Report Pursuant to Section 13 or 15(d) of the
                               Securities Exchange Act of 1934
                  For the Transition Period From            to
                                                 -----------  -----------------

                        Commission file number 001-12277

                              ACNielsen Corporation
-------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)

             Delaware                                   06-1454128
    --------------------------             ------------------------------------
     (State of incorporation)              (I.R.S. Employer Identification No.)

   177 Broad Street, Stamford, Connecticut                        06901
  ------------------------------------------                   ------------
   (Address of principal executive offices)                     (Zip Code)

Registrant's telephone number, including area code: (203) 961-3000.

           Securities registered pursuant to Section 12(b) of the Act:

                                                   Name of each exchange
     Title of each class                            on which registered
     -------------------                           ---------------------
Common Stock, par value $.01 per share             New York Stock Exchange
Preferred Share Purchase Rights                    New York Stock Exchange

        Securities registered pursuant to Section 12(g) of the Act: None

         Indicate by check mark whether the registrant (1) has filed all reports
required by Section 13 or 15(d) of the  Securities  Exchange  Act of 1934 during
the preceding 12 months and (2) has been subject to such filing requirements for
the past 90 days. Yes X No

          Indicate by check mark if disclosure of delinquent  filers pursuant to
Item 405 of Regulation S-K is not contained  herein,  and will not be contained,
to the best of  registrant's  knowledge,  in  definitive  proxy  or  information
statements  incorporated  by  reference  in Part  III of this  Form  10-K or any
amendment to this Form 10-K.  X
                            -----
         As of January 31, 2000,  57,816,150 shares of Common Stock of ACNielsen
Corporation were outstanding. The aggregate market value of the shares of Common
Stock  held  by  nonaffiliates  of  the  registrant   (based  upon  its  closing
transaction  price on the Composite Tape on January 31, 2000) was  approximately
$1,181 million.*

*Calculated by excluding all shares held by executive  officers and directors of
the  registrant,  without  conceding that all such persons are affiliates of the
registrant for purposes of the Federal securities laws.

                       Documents Incorporated by Reference
                      -------------------------------------
        Parts I and II: Portions of Registrant's Annual Report to Shareholders
                        for the 1999 Fiscal Year.

        Part III:       Portions of Registrant's Proxy Statement dated
                        March 10, 2000.

              The Index to Exhibits is located on Pages 17 to 19.

<PAGE>

                                     PART I

         As used in this report,  except where the context indicates  otherwise,
the  terms  "Company"  and  "ACNielsen"  mean  ACNielsen   Corporation  and  all
subsidiaries  consolidated in the financial  statements  incorporated  herein by
reference.

ITEM 1. BUSINESS

General

         ACNielsen Corporation began operating as an independent,  publicly-held
company  on  November  1,  1996  (the  "Distribution  Date")  as a result of the
distribution  (the  "Distribution")  on  that  date  by  The  Dun  &  Bradstreet
Corporation ("D&B") to D&B's shareholders of the Company's $.01 par value Common
Stock,  at a distribution  ratio of one share of the Company for three shares of
D&B. As part of a reorganization of its businesses,  D&B also distributed all of
the  outstanding  common stock of  Cognizant  Corporation  ("Cognizant")  on the
Distribution Date.

         ACNielsen   Corporation,   which  has  its  headquarters  in  Stamford,
Connecticut,  was  incorporated  in the State of Delaware on April 30, 1996 as a
wholly-owned  subsidiary of D&B for the purpose of effecting  the  Distribution.
ACNielsen  Corporation operates principally through subsidiaries and the Company
generally  is  comprised  of the  former  D&B  businesses  that  deliver  market
research,  information  and  analysis to the  worldwide  consumer  products  and
services  industries,   certain  businesses  acquired  since  the  Distribution,
including  ACNielsen  BASES and ACNielsen EDI, and new ventures formed since the
Distribution, principally ACNielsen eRatings.com.

Description of Business

         ACNielsen is a global leader in delivering market research, information
and  analysis  to the  consumer  products  and  services  industries.  ACNielsen
services are offered in over 100 countries around the globe.  ACNielsen provides
its clients with market research, information and analysis for understanding and
making critical decisions about their products and their markets. ACNielsen also
conducts  media  and  entertainment   information   businesses,   including  its
television  audience  measurement  business which operates  outside the U.S. and
Canada.

         ACNielsen  operates  outside  the  United  States  through  a number of
subsidiaries,  affiliates and joint ventures. In 1999, nearly 69% of ACNielsen's
revenues were generated outside the United States.

         ACNielsen operates across a wide spectrum of research  services.  These
services  generally  fall into four  categories:  Retail  Measurement  Services,
Customized  Research  Services,  Media and  Entertainment  Services and Consumer
Panel Services.

         ACNielsen also offers its clients, through a wide range of modeling and
analytic  services,  custom-tailored  insights into complex  marketing and sales
issues.  Typical  assignments  range from  marketing-mix  modeling  to  category
management analysis,  including topics as diverse as pricing strategy,  consumer
driven market  structure,  variety  management,  outlet  switching and promotion
tactics.

         ACNielsen's clients include  distributors and manufacturers of consumer
packaged goods and other products,  retailers and brokers,  as well as companies
operating  in  various  service  industries   (including   financial   services,
telecommunications,  advertising,  television  and  radio  broadcasting,  motion
pictures and publishing).

         ACNielsen   operates  in  one  industry   segment,   Market   Research,
Information and Analysis Services. The approximate revenues attributable to each
category of service  provided by ACNielsen were as follows for the periods shown
(in millions of dollars):

                                             Year ended December 31,
                                      -------------------------------------
                                          1999          1998          1997
                                          ----          ----          ----
Retail Measurement                     $ 1,034         $ 999         $ 987
Customized Research                        263           213           191
Media and Entertainment *                  114           110           120
Consumer Panel                             114           103            94
                                     ----------     ---------     ---------
           Total                        $1,525        $1,425        $1,392
                                     ==========     =========     =========

* Reported revenue for Media and Entertainment  declined in 1998, as a result of
the transfer of the Latin  American  media business to a joint venture (see page
4).

                                       1
<PAGE>


         The number of full-time equivalent employees of the Company at December
31, 1999 was approximately 21,000. Of this number, approximately 3,248 full-time
equivalent  employees  are located in the United  States,  and none of these are
represented  by labor  unions.  ACNielsen's  non-U.S.  employees  are subject to
numerous  labor council or similar  relationships  which vary due to the diverse
cultures in which ACNielsen  operates.  Management believes that labor relations
generally are  satisfactory  and have been  maintained in a normal and customary
manner.

         On February 18, 2000, the Company  announced  Operation Leading Edge, a
plan to  accelerate  the  Company's  growth  beyond  2000  through  a series  of
business-building  initiatives  designed to  accelerate  both revenue and profit
growth by enhancing  products and services,  addressing  changing  client needs,
improving  efficiency  and reducing the  Company's  cost  structure.  Additional
information  regarding  Operation  Leading Edge is  contained  in  "Management's
Discussion and Analysis of Financial  Condition and Results of Operations" which
is incorporated by reference into this Form 10-K in response to Part II, Item 7.

Retail Measurement Services

         Through its Retail  Measurement  Services the Company  delivers data to
clients on product  movement  and related  causal  information  (i.e.,  coupons,
in-store promotions and other information or conditions  affecting sales) on six
continents.  Introduced in 1933, ACNielsen's original Food and Drug Indexes soon
became the industry  measurement tool for  understanding the dynamics of product
sales. Over the years,  technology has dramatically improved ACNielsen's ability
to  collect  and  analyze   information   from  retailers  and  consumers.   The
availability of scanning  technology in retail outlets in many countries  around
the world has broadened both the scope and capabilities of ACNielsen's  original
retail indexes.

         ACNielsen's  Retail  Measurement  Services  are  available  in  over 80
countries.  Retail  Measurement  Services  include  scanning  and  retail  audit
services,  account level reports,  decision support,  merchandising and category
management  services and marketing and sales  applications,  along with modeling
and analytic services.

Scanning

         Using the bar codes  printed on  products  and  scanners  installed  in
retail outlets,  ACNielsen gathers  information from stores in the United States
and Canada and certain  countries  in Europe,  Latin  America and Asia  Pacific.
ACNielsen's  clients  can  monitor  performance  trends and  evaluate  price and
promotion  effectiveness  by tracking and  forecasting  non-promoted  as well as
promotional product movement.

         ACNielsen  offers a number  of  additional  services  to  enhance  each
customer's understanding of its markets. Among these are services reporting data
by  customer-defined  markets,  services  aggregating  consumer data in multiple
channels,  and  services  disaggregating  data to  satisfy  particular  needs of
clients.

Retail Audit

         In  addition  to  scanning  data  (which is  available  only in certain
industry sectors and in certain countries), retail audit is a valuable source of
market  information as a basic  measurement tool and as a supplement to scanning
data.  Retail  audit  involves the  continuous  measurement  by ACNielsen  field
auditors of product and category  performance in the retail trade, and reporting
to clients on sales,  distribution,  stocks,  prices  and other  measures  which
assist them in marketing and trade negotiations.

         Retail Audit is divided into industry  segments,  traditionally  called
Indexes.  The Food Index is generally the largest, but there are also Health and
Beauty,  Durables,  Confectionery,  Liquor, Cash & Carry, plus a number of other
Indexes specific to certain countries.

In-Store Observation

         ACNielsen field auditors  collect data on where products are located in
stores,  how many facings they have, on which shelves they are positioned,  etc.
(broken down by store type,  store size and geographic  region).  ACNielsen also
collects causal data.  These data add to market insights and help to monitor the
implementation  of  retailer/manufacturer  promotional  agreements  in  terms of
numeric distribution, space allocation and promotional execution.

Levels of Information

         ACNielsen provides information and insight to clients from a macro to a
micro  level.  Whether  on a  country,  market  or  individual  retailer  level,
ACNielsen generally measures the competitive  environment in which manufacturers
and retailers conduct business.  In some countries ACNielsen also provides store
census data which allow  retailers  and  manufacturers  to  understand  consumer
behavior within a group of stores as well as within a retail trading area.

                                       2
<PAGE>

         ACNielsen's  account-specific  information provides sales and marketing
managers with a comprehensive array of retailer-specific sales and merchandising
information,   producing  reports  of  product  and  category  performance  that
encompass an organization's own brands as well as competing brands.

         On a global basis,  ACNielsen sells and provides to its  multi-national
clients  international  reports within and across country  boundaries.  Products
include an International  Database  (periodic reports of a multi-country  retail
database) and an International  Market Report (a one-time report on a market and
its competitive environment).

Decision Support

         ACNielsen uses its rich data sources to extract business  insights that
are used by  clients  to  create  competitive  advantage.  ACNielsen's  decision
support  software  offers a robust  environment  for data access,  manipulation,
analysis  and final  presentation  through  fast access to  ACNielsen as well as
clients'  internal  data.  This  decision  support  software  can  also  uncover
"exceptional"    information   through    sophisticated    analytical   modeling
capabilities.  ACNielsen  information  can be  delivered  on-line  and via other
electronic media (CD-ROM, diskette), as well as through the Internet and printed
reports.

         ACNielsen INF*ACT Workstation software is ACNielsen's flagship software
offering. The Workstation is an open, Windows-based, analytical and applications
development tool set used worldwide by ACNielsen clients.  ACNielsen's  SalesNet
provides  fast,  easy access to pre-run  analyses  delivered  via the  Internet.
ACNielsen  also offers a robust,  proprietary  and ad-hoc  reporting tool called
Workstation Plus which allows users to access,  query and build advanced reports
for INF*ACT and/or relational databases.

         ACNielsen also offers a series of  Windows-based  intelligent  business
applications that enhance ACNielsen INF*ACT  Workstation  functionality,  giving
clients the ability to plan, analyze and execute successful  marketing and sales
programs.  These applications  include  Opportunity  Explorer,  Business Review,
Spotlight, NITE, and others.

         In addition,  ACNielsen offers sophisticated  category management tools
such as Business Manager, SPACEMAN and PRICEMAN.

Customized Research Services

         Customized  Research  Services  are used by  manufacturers,  retailers,
financial  institutions and other service  organizations that seek to understand
the position of their  current,  new and  proposed  products and services in the
marketplace.  With  customized  research  capabilities  in more than half of the
countries  in which it  operates,  ACNielsen  is  well-positioned  to offer  its
clients,  including both  manufacturers  and retailers,  consumer  insights from
customized  research as well as an  understanding of dynamic new markets such as
entertainment, fast foods, financial services and telecommunications.

         In June  1998,  the  Company  acquired  BBI  Marketing  Services,  Inc.
("ACNielsen  BASES").  ACNielsen  BASES,  the global  leader in  simulated  test
marketing,  provides fast moving  consumer goods  marketers with sales estimates
and  diagnostic  analysis  for  their new  business  initiatives.  In  addition,
ACNielsen VANTIS, a business unit of ACNielsen BASES, focuses on researching new
business   initiatives   for  marketers   outside  fast  moving  consumer  goods
categories.  The addition of ACNielsen BASES enhanced the Company's portfolio of
advanced modeling and analytical services.

         In 1998, the Company launched  Winning Brands,  a proprietary  research
product that helps  clients  manage and  leverage  their brand  equity.  Winning
Brands follows the successful  1997  introduction of Customer eQ, a product that
measures customer satisfaction and loyalty.

         In  addition  to services  at the  country  level and  ACNielsen  BASES
services, ACNielsen offers multi-country customized studies at both the regional
and global levels and has  specialist  offices in Hong Kong,  London,  New York,
Tokyo,  Toronto and Singapore to carry out customized  research in Asia Pacific,
Western Europe, North and South America, the Middle East and Africa.

Media and Entertainment Services

Media

         The  information  produced by ACNielsen  Media  International  includes
audience estimates for television, radio and print, plus advertising expenditure
measurement  and  customized  media  research.  Television and radio ratings and
readership data are used by program producers,  broadcasters,  publishers, media
planners, airtime buyers and others, on behalf of manufacturers/advertisers  and
media  owners,  to  determine  the best,  most  cost-efficient  way of  reaching
clients.

                                       3
<PAGE>

         ACNielsen  Media   International's   television  audience   measurement
services,  which  operate  outside the United  States and Canada,  generally use
representative  panels  of  households,  each  with a  meter  attached  to  each
television  in the  household.  The  meters  register  viewership,  which can be
matched with broadcast  information to identify viewing of specific programs. In
a few countries  written diaries are used instead of, or in addition to, meters,
with viewers  writing the channels,  programs and the times  watched.  With both
meter and diary panels,  aggregate individual and household viewing is projected
to represent national viewing habits.

         Outside of Latin America,  ACNielsen's  television audience measurement
services are operational in 17 countries, primarily in the Asia Pacific region.

         In connection  with the  Distribution,  ACNielsen  entered into the TAM
Master  Agreement (the "TAM Master  Agreement")  with Cognizant  relating to the
conduct of the television  audience  measurement  business (the "TAM Business").
See "TAM  Master  Agreement"  below for  further  information  on the TAM Master
Agreement.

         ACNielsen Media  International's  advertising  expenditure  measurement
services,  which are  marketed in 31  countries,  provide to clients,  primarily
advertising agencies and manufacturers/advertisers, verification that individual
commercials or commercial  campaigns ran as contracted,  report the costs of the
manufacturers'  own and competitors'  advertisements  and alert users to new and
competitive ad campaigns.

         Effective  January  1998,  the  Company  became  a  partner  in a joint
venture,  IBOPE Media  Information  and  transferred  its Latin  American  media
business to the joint venture.  The joint  venture,  operating in Latin America,
offers television audience measurement  services in ten markets,  provides radio
audience  measurement  services in two  countries  and  advertising  expenditure
measurement services in four countries.

         Media Monitoring Services Ltd. was acquired on November 30, 1999 and
is a provider of advertising  measurement  services in
the United Kingdom, Australia, and Asia.

Entertainment

         In late 1997,  ACNielsen acquired  Entertainment Data, Inc. ("ACNielsen
EDI"),  a provider of  information  for the motion  picture  industry.  Based in
Hollywood,  California, ACNielsen EDI provides box-office information to studios
and  exhibitors in the motion picture  industry.  This  information  helps users
decide where and for how long a movie will play,  as well as the  allocation  of
advertising and promotional  dollars.  ACNielsen EDI also provides  creative and
consumer  research to the studios.  ACNielsen EDI provides services in the U.S.,
Canada, U.K., Germany, Spain, France, Austria,  Ireland,  Mexico,  Argentina and
Australia.

Internet

         In  September  1999,  ACNielsen  and  NetRatings,  Inc.  ("NetRatings")
entered into a venture to  establish  ACNielsen  eRatings.com  ("eRatings.com").
ACNielsen has an 80.1% ownership  interest in the venture with NetRatings owning
the  remainder.   eRatings.com  is  primarily  engaged  in  providing   Internet
measurement services. The venture, either directly or through joint ventures, is
expected to operate in all major  geographic  regions  worldwide  other than the
United States and Canada and it plans to roll out the service  initially in five
countries by the end of the first quarter of 2000.

         ACNielsen's   proprietary  sampling  methodology  is  used  to  form  a
representative  panel.  Once an  individual  or  household  agrees  to  become a
panelist,  software is  installed  on the  panelist's  PC. The  software  tracks
individuals' Internet usage on a real time basis. Aggregate information and data
are then made available on a weekly and monthly basis through a website.

         The software requires virtually no panelist intervention once installed
and can be automatically  upgraded.  The software collects and delivers Internet
usage  data using  NetRatings'  proprietary  collection  software.  This  allows
panelists  to freely  access the  Internet  without  having to worry  about data
collection.

         Once the software is installed,  it collects real-time data by tracking
user activity  including the sites visited,  duration of visits and the duration
and  frequency of sessions.  The  technology  is also able to track  advertising
activity including the actual ad banners viewed, advertisers,  sites the ads ran
on, and ads clicked on. The software  tracks user  profiles,  including the age,
gender, marital status, education, occupation, income and ethnicity of the panel
member.

         eRatings.com's  Internet Measurement Service will be marketed under the
Nielsen//NetRatings   brand  and  will  provide  clients  with  the  ability  to
accurately track and analyze Internet audience behavior, in addition to in-depth
research reports across a variety of Internet related subjects.

                                       4
<PAGE>

         eRatings.com  has  exclusive  rights to market the  Nielsen//NetRatings
Internet Measurement Service in countries outside the United States,  Canada and
Japan. In France the  Nielsen//NetRatings  service will be offered via a company
called  Mediametrie  eRatings.com,  which is a venture  among  Mediametrie,  the
French audience measurement and survey company, NetRatings and eRatings.com.  In
March 2000,  eRatings.com  formed a joint  venture with IBOPE Media  Information
called IBOPE  eRatings.com that will launch the  Nielsen//NetRatings  service in
Latin America. Also, in March 2000,  eRatings.com acquired an ownership interest
in the Japanese  venture  previously  established  by  NetRatings to provide the
Nielsen//NetRatings service in Japan.

Consumer Panel Services

         Consumer  Panel  Services  help   organizations   achieve   competitive
advantage by applying  consumer  insights  derived from the  ACNielsen  consumer
panel  database.  With a  comprehensive  portfolio  of tools for  reporting  and
analysis,  ACNielsen  measures the  multi-faceted  dynamics of consumer behavior
across all outlets including:  consumer demographics,  percentages of households
purchasing,  products and quantities purchased, frequency of purchases, shopping
trips and shopping expenditures,  price and promotion  sensitivity,  price paid,
and attitude and usage information.

         The   ACNielsen   Consumer   Panel,   called   Homescan,   consists  of
approximately 55,000 demographically balanced U.S. households that use hand-held
scanners  to record  every  bar-coded  item  purchased  and,  outside the United
States, is comprised of more than 80,000 households in 19 countries.

         ACNielsen  employs  multiple data collection  processes  throughout the
world. In the United States and several other countries  covering  approximately
90% of total panel  households  worldwide,  ACNielsen  installs in-home scanners
with which  panelists  scan  items at home as they  unpack  purchases  from each
shopping trip,  recording price,  promotions and quantity purchased,  as well as
the age and gender of the shopper and intended user.  Information detailing each
shopping trip is transmitted, via telephone lines, to ACNielsen.

         Consumer  panel  applications  can be used by  both  manufacturers  and
retailers to understand demographics and purchasing habits of consumers. As with
all information derived from the ACNielsen Consumer Panel, data capture activity
is from  all  outlet  types  including  grocery,  drug,  mass  merchandiser  and
warehouse  clubs.  Clients can choose  from a wide  variety of  applications  or
analyses, from syndicated to customized and basic to complex. ACNielsen offers a
full suite of syndicated  category management  applications.  These reports give
manufacturers  and  retailers  insights  into cross  outlet  shopping,  consumer
loyalty  and the value of  consumer  segments  such as the value of core  versus
occasional shoppers.

         ACNielsen also provides delivery tools that allow marketers to process,
chart and analyze ACNielsen Consumer Panel information quickly and easily. Among
these are CD-ROM  tools and  Panel*Fact  for Windows,  which enable  managers to
create customized  reports to meet their individual  analytic needs and to share
data and analyses with various members within an organization.

Relationship Among ACNielsen, D&B and Cognizant after the Distribution

         Prior to the  Distribution,  D&B,  Cognizant and ACNielsen entered into
certain  agreements  (the  "Spin   Agreements")   governing  their  relationship
subsequent to the Distribution and providing for the allocation of tax, employee
benefits and certain  other  liabilities  and  obligations  arising from periods
prior to the Distribution. The following description summarizes terms of certain
of  these  agreements,  but is  qualified  by  reference  to the  texts  of such
agreements  which  were  previously  filed  with  the  Securities  and  Exchange
Commission.

         In June 1998, D&B changed its name to R.H.  Donnelley  Corporation  and
spun off a company now named The Dun & Bradstreet  Corporation  ("New D&B"), and
Cognizant changed its name to Nielsen Media Research,  Inc. ("NMR") and spun off
a company named IMS Health Incorporated ("IMS Health"). As required by the terms
of the Distribution  Agreement referred to below, each of New D&B and IMS Health
has provided an  undertaking  to the Company to be jointly and severally  liable
with its former parent company for any liabilities of such former parent company
arising out of the Spin Agreements.  In July 1999, IMS Health distributed shares
of  Gartner  Group,  Inc.  ("Gartner")  class B stock  to its  shareholders.  In
connection with such  distribution  and pursuant to the  Distribution  Agreement
referred to below,  Gartner provided an undertaking to the Company to be jointly
and severally  liable for any  liabilities of Cognizant (now NMR) arising out of
the Spin Agreements.

Distribution Agreement

         D&B,  Cognizant and  ACNielsen  entered into a  Distribution  Agreement
providing for, among other things,  certain corporate  transactions  required to
effect  the  Distribution  and  other  arrangements  among  D&B,  Cognizant  and
ACNielsen  subsequent  to the  Distribution.  In  particular,  the  Distribution
Agreement  defined  the  assets  and  liabilities  allocated  to and  assumed by
Cognizant  and those  allocated to and assumed by  ACNielsen.  The  Distribution
Agreement  also defined  what  constituted  the  "Cognizant  Business"  and what
constituted the "ACNielsen Business".  It also provided for, among other things,
assumptions of liabilities and cross indemnities designed to allocate generally,
effective  as  of  the  Distribution  Date,  financial  responsibility  for  the
liabilities  arising out of or in connection with (i) the Cognizant  Business to
Cognizant,  (ii) the  ACNielsen  Business  to  ACNielsen  and  (iii)  all  other
liabilities to D&B.

5
<PAGE>

Indemnity and Joint Defense Agreement

         D&B,  Cognizant  and  ACNielsen  entered into the  Indemnity  and Joint
Defense  Agreement  pursuant  to which they  agreed (i) to certain  arrangements
allocating potential liabilities ("IRI Liabilities") that may arise out of or in
connection with the IRI Action, as defined below in "Item 3, Legal Proceedings",
and (ii) to conduct a joint  defense of such  action.  See  "Relationship  Among
ACNielsen,  D&B and  Cognizant  after the  Distribution"  above for  information
regarding name changes and certain  post-Distribution events affecting Cognizant
and D&B.

         The Indemnity and Joint Defense Agreement  provides that ACNielsen will
assume  exclusive  liability for IRI  Liabilities  up to a maximum  amount to be
determined  at the time  such  liabilities,  if any,  become  payable  (the "ACN
Maximum Amount") and that Cognizant and D&B will share liability equally for any
amounts in excess of the ACN  Maximum  Amount.  The ACN  Maximum  Amount will be
determined by an investment  banking firm as the maximum amount which  ACNielsen
is able to pay after giving effect to (i) any plan submitted by such  investment
bank which is  designed  to  maximize  the claims  paying  ability of  ACNielsen
without  impairing the investment  banking firm's ability to deliver a viability
opinion (but which will not require any action requiring stockholder  approval),
and (ii) payment of related fees and  expenses.  For these  purposes,  financial
viability means the ability of ACNielsen,  after giving effect to such plan, the
payment of related fees and expenses and the payment of the ACN Maximum  Amount,
to pay its debts as they become due and to finance  the current and  anticipated
operating and capital  requirements of its business,  as  reconstituted  by such
plan, for two years from the date any such plan is expected to be implemented.

         In addition,  ACNielsen  agreed to certain  restrictions on payments of
dividends and share repurchases  above specified  levels.  ACNielsen also agreed
not to engage in mergers, acquisitions or dispositions,  including joint venture
investments, if, after giving effect to any such transaction, ACNielsen would be
unable  to meet a  specified  fixed  charge  coverage  ratio,  and,  if any such
transaction  involves  aggregate  consideration  in excess of $50 million,  then
ACNielsen is also  required to receive and to cause to be delivered to Cognizant
and D&B an investment banker's fairness opinion.

         The  Indemnity  and Joint  Defense  Agreement  also sets forth  certain
provisions governing the defense of the IRI Action pursuant to which the parties
agree to be  represented  by the same counsel.  Legal  expenses are to be shared
equally by the three parties.

TAM Master Agreement

         Cognizant  (now called NMR) and  ACNielsen  entered into the TAM Master
Agreement  relating  to the  conduct  of  the  television  audience  measurement
business (the "TAM Business").

         Pursuant to the TAM Master  Agreement and certain  ancillary  trademark
and technology licensing agreements (together with the TAM Master Agreement, the
"TAM Agreement"), Cognizant or a newly established entity is required to license
to ACNielsen (i) a non-exclusive  right to use certain  trademarks in connection
with the TAM  Business  outside the United  States and Canada for five years and
(ii) a non-exclusive right to use specified technology in Australia, Ireland and
India in  connection  with the TAM Business for five years or such longer period
as is required to fulfill contractual  obligations  existing on the Distribution
Date.

Competition

         ACNielsen  has numerous  competitors  in its various  lines of business
throughout the world. Some are companies with diverse product and service lines;
others have more limited product and service  offerings.  Competition comes from
companies  specializing in marketing research; the in-house research departments
of  manufacturers  and  advertising  agencies;   retailers  selling  information
directly or through brokers;  information management and software companies; and
consulting and accounting firms.

         In Retail Measurement Services, ACNielsen's principal competitor in the
United  States is  Information  Resources,  Inc.  (IRI).  IRI is also  active in
Canada,  Europe and Latin America by itself and through joint  ventures with GfK
(Germany), Taylor Nelson Sofres in Europe, and other companies, and is expanding
globally.

         In Customized  Research Services,  a significant  competitor is Kantar,
the marketing  research arm of WPP Group Plc.,  which operates  globally through
BMRB International, Millward Brown International and Research International.

         In Media and Entertainment  Services,  significant  competitors include
Taylor Nelson Sofres,  GfK, AGB Media Services,  and Video Research (Japan) and,
with respect to Internet  Measurement  Services,  Media  Metrix,  NetValue,  IMR
Worldwide and PC Data.

6
<PAGE>

         In Consumer Panel Services,  significant competitors include IRI in the
United States, and the Europanel consortium, which includes Taylor Nelson Sofres
and GfK, operating in Europe. NPD also competes in this area.

         Principal   competitive  factors  include   innovation,   the  quality,
timeliness,  reliability and  comprehensiveness of analytical services and data,
flexibility  in tailoring  services to client needs,  price,  and geographic and
market coverage.

Non-U.S. Operations

         As indicated above,  ACNielsen engages in a significant  portion of its
business  outside of the United States,  with nearly 69% of its revenues in 1999
being generated through non-U.S.  sources.  ACNielsen's non-U.S.  operations are
subject to the usual risks  inherent in carrying on business  outside the United
States,   including   fluctuations  in  relative   currency   values,   possible
nationalization,  expropriation,  price controls or other restrictive government
actions. ACNielsen believes that the risk of nationalization or expropriation is
reduced because its products are services and information,  rather than products
which require manufacturing facilities or the use of natural resources.

Intellectual Property

         ACNielsen owns and controls trade  secrets,  confidential  information,
trademarks,  trade names,  copyrights  and other  intellectual  property  rights
which,  in the aggregate,  are of material  importance to ACNielsen's  business.
Management of ACNielsen  believes that the  "ACNielsen"  name and related names,
marks and logos are of material  importance to ACNielsen.  ACNielsen is licensed
to use certain  technology  and other  intellectual  property  rights  owned and
controlled  by others,  and,  similarly,  other  companies  are  licensed to use
certain technology and other  intellectual  property rights owned and controlled
by ACNielsen.

         Pursuant to an  Intellectual  Property  Agreement (the "IP  Agreement")
among D&B, Cognizant (now called NMR) and ACNielsen,  entered into in connection
with  the  Distribution,  ACNielsen  has  exclusive  rights  to  the  use of the
"ACNielsen"  name worldwide;  however,  ACNielsen's  future use of the "Nielsen"
name  standing  alone is  prohibited  and,  as a part of a name  describing  new
products  and  services to be  offered,  is subject to certain  limitations.  In
addition,  the IP Agreement also provided for the establishment of a new entity,
jointly  owned  by  Cognizant  and  ACNielsen,  into  which  certain  trademarks
incorporating  or  relating  to the  "Nielsen"  name in various  countries  were
assigned.  This entity is obligated to license such trademarks on a royalty-free
basis to Cognizant or ACNielsen for use in a manner consistent with the terms of
the IP Agreement  and for purposes of  conducting  their  respective  businesses
after the  Distribution,  and is responsible for preserving the quality of those
trademarks and minimizing  any risk of possible  confusion.  Pursuant to the TAM
Agreement, Cognizant is required to grant ACNielsen a non-exclusive right to use
certain trademarks and technology, as described in "TAM Master Agreement" above.
ACNielsen  shall not be licensed to use any such  trademarks  or  technology  in
connection  with the  conduct of the TAM  Business  within the United  States or
Canada.

         The  technology  and other  intellectual  property  rights  licensed by
ACNielsen  are  important  to its  business,  although  management  of ACNielsen
believes that  ACNielsen's  business,  as a whole, is not dependent upon any one
intellectual property or group of such properties.

         The names of ACNielsen's  products and services  referred to herein are
registered or  unregistered  trademarks or service marks owned by or licensed to
ACNielsen or its subsidiaries.

Forward-Looking Statements

         Certain statements contained herein or incorporated herein by reference
are forward looking. These may be identified by the use of forward-looking words
or phrases,  such as "anticipate,"  "believe," "expect,"  "designed,"  "intend,"
"could,"  "should,"  "planned,"   "estimated,"   "potential,"  "target,"  "aim,"
"objective" and "goal," among others. In addition,  the Company may from time to
time make oral forward-looking  statements. In connection with the "safe harbor"
provisions of the Private Securities  Litigation Reform Act of 1995, the Company
is hereby  identifying  important  factors  that could cause  actual  results to
differ materially from those contained in forward-looking  statements made by or
on behalf of the  Company.  Any such  statement is qualified by reference to the
following cautionary statement.

         Risks and  uncertainties  that may affect the operations,  performance,
development and results of the Company's business include:  (i) the availability
of  retail  sources  that are  willing  to sell  data to the  Company  at prices
acceptable  to the  Company;  (ii)  changes in general  economic or  competitive
conditions  which  impact  the  Company's  clients'  demand  for  the  Company's
services;   (iii)  significant  price  and  service   competition;   (iv)  rapid
technological  developments  in the  collection,  manipulation  and  delivery of
information;  (v) the Company's  ability to complete the  implementation  of its
Euro plans on a timely basis; (vi) the likely  incurrence of significant  losses
by ACNielsen eRatings.com while its business is being developed,  the difficulty
of forecasting its future revenues and costs and  uncertainties  associated with
the  international  development  of  an  Internet  ratings  service;  (vii)  the
Company's  ability  to  successfully   implement  Operation  Leading  Edge  (its
announced plan to enhance its products and services,  address  changing  clients
needs,  improve  efficiency  and reduce its cost  structure)  and to achieve the
estimated  levels of revenue and profit growth  therefrom;  (viii) the impact of
foreign  currency  fluctuations  since  so much of the  Company's  earnings  are
generated  abroad;  (ix) the degree of acceptance of new product  introductions;
(x) the uncertainties of litigation,  including the IRI Action; as well as other
risks and uncertainties  detailed from time to time in the Company's  Securities
and Exchange Commission filings.

7
<PAGE>

         Developments  in any of the areas  referred  to above  could  cause the
Company's  results to differ from  results that have been or may be projected by
or on behalf of the Company.  The Company  cautions that the  foregoing  list of
important factors is not exclusive. The Company does not undertake to update any
forward-looking  statement that may be made from time to time by or on behalf of
the Company.

Financial Information about Segments

         The response to item 101(d) of Regulation S-K is incorporated herein by
reference to Note 15 Operations by Geographic Segment on Pages 53-54 of the 1999
Annual Report.  Additionally,  long-lived assets totaled $266,014,  $260,842 and
$151,269 in the U.S. and  $412,061,  $391,118 and $367,334 (in thousands of U.S.
dollars) in the Non-U.S. in 1999, 1998 and 1997, respectively.

ITEM 2.  PROPERTIES

         ACNielsen's  real  properties  are  geographically  distributed to meet
sales and operating requirements  worldwide.  Most of ACNielsen's properties are
leased from third  parties,  including D&B and NMR.  ACNielsen's  properties are
generally  considered to be both suitable and adequate to meet current operating
requirements and virtually all space is being utilized.

ITEM 3. LEGAL PROCEEDINGS

         On July 29, 1996, Information Resources, Inc. ("IRI") filed a complaint
in the United  States  District  Court for the  Southern  District  of New York,
naming as defendants  D&B, A.C.  Nielsen  Company  (which is a subsidiary of the
Company,  "ACNielsenCo")  and I.M.S.  International,  Inc.  ("IMS"),  formerly a
subsidiary  of Cognizant  Corporation  ("Cognizant")  and a  predecessor  of IMS
Health Incorporated (the "IRI Action").

         The complaint alleges various violations of the United States antitrust
laws:  (1) a  violation  of  Section 1 of the  Sherman  Act  through  an alleged
practice of tying ACNielsenCo  services in different countries or of ACNielsenCo
and IMS  services;  (2) a  violation  of Section 1 of the  Sherman  Act  through
alleged  unreasonable  restraints of trade consisting of the contracts described
above and through alleged long-term agreements with multi-national  clients; (3)
a violation  of Section 2 of the Sherman Act for  monopolization  and  attempted
monopolization  of export markets  through  alleged  exclusive data  acquisition
agreements  with  retailers in foreign  countries,  the  contracts  with clients
described  above,  and other means;  (4) a violation of Section 2 of the Sherman
Act for attempted monopolization of the United States market through the alleged
exclusive data agreements  described above,  predatory pricing, and other means;
and (5) a violation of Section 2 of the Sherman Act for an alleged use of market
power in export  markets to gain an unfair  competitive  advantage in the United
States.

         The  complaint  also alleges two claims of tortious  interference  with
contract and tortious  interference  with a prospective  business  relationship.
These claims relate to the  acquisition  by defendants of Survey  Research Group
Limited  ("SRG").  IRI alleges that SRG violated an alleged  agreement  with IRI
when it agreed to be acquired by defendants and that  defendants  induced SRG to
breach that agreement.

         IRI's complaint alleges damages in excess of $350 million, which amount
IRI has asked to be trebled under the antitrust  laws.  IRI also seeks  punitive
damages in an unspecified amount.

         By notice of motion  dated  October 15, 1996,  defendants  moved for an
order  dismissing all claims in the complaint.  On May 6, 1997 the United States
District  Court for the  Southern  District of New York issued a decision on the
motion to dismiss.  The Court dismissed IRI's claim of attempted  monopolization
in the United States with leave to replead  within sixty days.  The Court denied
defendants' motion with respect to the remaining claims in the complaint.

         On  June  3,  1997,  defendants  filed  an  answer  and  counterclaims.
Defendants  denied all  material  allegations  of the  complaint.  In  addition,
ACNielsenCo asserted  counterclaims against IRI alleging that IRI has made false
and misleading statements about ACNielsenCo's services and commercial activities
and that such conduct constitutes a violation of Section 43(a) of the Lanham Act
and unfair competition. ACNielsenCo seeks injunctive relief and damages.

         On July 7, 1997, IRI filed an amended  complaint seeking to replead the
claim of attempted monopolization in the United States, which had been dismissed
by the Court in its May 6, 1997  decision.  By notice of motion dated August 18,
1997, defendants moved for an order dismissing the amended claim. On December 1,
1997, the Court denied defendants' motion. Discovery is currently ongoing.

8
<PAGE>

        In connection  with the IRI Action,  D&B,  Cognizant  (the former parent
company of IMS) and the Company  entered  into an  Indemnity  and Joint  Defense
Agreement (the "Indemnity and Joint Defense  Agreement")  pursuant to which they
agreed  (i) to  certain  arrangements  allocating  potential  liabilities  ("IRI
Liabilities")  that may arise out of or in  connection  with the IRI  Action and
(ii) to conduct a joint defense of such action. In particular, the Indemnity and
Joint  Defense  Agreement  provides  that  the  Company  will  assume  exclusive
liability  for IRI  Liabilities  up to a maximum  amount to be calculated at the
time such liabilities,  if any, become payable (the "ACN Maximum  Amount"),  and
that Cognizant and D&B will share liability equally for any amounts in excess of
the ACN  Maximum  Amount.  The ACN  Maximum  Amount  will  be  determined  by an
investment  banking firm as the maximum  amount which the Company is able to pay
after giving effect to (i) any plan submitted by such  investment  bank which is
designed to maximize the claims paying ability of the Company without  impairing
the investment  banking firm's ability to deliver a viability opinion (but which
will not require any action requiring stockholder approval), and (ii) payment of
related fees and expenses.  For these  purposes,  financial  viability means the
ability of the Company, after giving effect to such plan, the payment of related
fees and expenses and the payment of the ACN Maximum Amount, to pay its debts as
they become due and to finance the current and anticipated operating and capital
requirements of its business,  as reconstituted by such plan, for two years from
the date any such plan is expected to be implemented.

        The  Indemnity  and  Joint  Defense   Agreement  also  imposes   certain
restrictions  on the payment of cash dividends and the ability of the Company to
purchase its stock.

        In June 1998 (i) D&B changed its name to R.H. Donnelley  Corporation and
spun off (the "D&B Spin") a company now named The Dun &  Bradstreet  Corporation
("New D&B"), and (ii) Cognizant changed its name to Nielsen Media Research, Inc.
("NMR")  and  spun  off  (the  "Cognizant  Spin") a  company  named  IMS  Health
Incorporated ("IMS Health").  Pursuant to the terms of a Distribution  Agreement
dated as of October 28, 1996 among the Company,  D&B and Cognizant,  New D&B was
required  as a  condition  to the D&B Spin,  and IMS  Health was  required  as a
condition to the  Cognizant  Spin, to undertake to the Company to be jointly and
severally  liable with its former parent  company for,  among other things,  the
obligations  of such former parent company under the Indemnity and Joint Defense
Agreement.  Each of New D&B and IMS Health did provide such  undertaking  to the
Company.

        Management  of  ACNielsen  is unable to  predict  at this time the final
outcome of the IRI Action or whether its resolution could materially  affect the
Company's results of operations, cash flows or financial position.

        The  Company  and its  subsidiaries  are also  involved  in other  legal
proceedings and litigation  arising in the ordinary  course of business.  In the
opinion of management, the outcome of such current legal proceedings, claims and
litigation,  if decided adversely,  could have a material effect on quarterly or
annual  operating  results  or cash  flows  when  resolved  in a future  period.
However, in the opinion of management,  these matters will not materially affect
the Company's consolidated financial position.

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

         Not applicable.


EXECUTIVE OFFICERS OF THE REGISTRANT

        Executive  officers are elected by the Board of Directors to hold office
at the pleasure of the Board of Directors.

        Listed below are the  executive  officers of the  registrant at March 1,
2000 and brief  summaries  of their  business  experience  during  the past five
years.

<TABLE>
<CAPTION>

        Name                                     Title                                           Age
       ------                                  ---------                                       -------
<S>                            <C>                                                                <C>
Nicholas L. Trivisonno         Chairman and Chief Executive Officer*                              52
Michael P. Connors             Vice Chairman*                                                     44
Robert J. Chrenc               Executive Vice President and Chief Financial Officer               55
Earl H. Doppelt                Executive Vice President and General Counsel                       46

  *Member of the Board of Directors.
</TABLE>


                                       9
<PAGE>


        Mr.  Trivisonno  was elected  Chairman  and Chief  Executive  Officer of
ACNielsen, effective May 1996; he served as Executive Vice President-Finance and
Chief Financial Officer of D&B (business information),  effective September 1995
through  November 1, 1996.  Prior  thereto,  he had served with GTE  Corporation
(telecommunications)  as Executive Vice  President-Strategic  Planning and Group
President,  effective  October  1993  through  July  1995.  He also  served as a
director of GTE Corporation from April 1995 through July 1995.

        Mr. Connors was elected Vice Chairman of ACNielsen,  effective May 1996;
he served as Senior Vice  President  of D&B  (business  information),  effective
April 1995 through November 1, 1996. Prior thereto, he had served as Senior Vice
President of American  Express  Travel  Related  Services  (travel and financial
services), effective September 1989 through March 1995.

        Mr. Chrenc was elected Executive Vice President and Chief Financial
Officer of ACNielsen,  effective June 1996. Prior thereto he was a Partner of
Arthur Andersen LLP (accounting), effective September 1979 through May 1996.

        Mr. Doppelt was elected  Executive Vice President and General Counsel of
ACNielsen,  effective  May 1996;  he had  served as Senior  Vice  President  and
General Counsel of D&B, effective May 1994 through November 1, 1996.



                                     PART II

ITEM 5.  MARKET FOR THE REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER
         MATTERS

         Information  in response to this Item is set forth under  Liquidity and
Capital  Resources,  Dividends  and Common Stock  Information  in  "Management's
Discussion  and Analysis of Financial  Condition and Results of  Operations"  on
Pages 34 and 36 of the 1999 Annual Report,  which  information  is  incorporated
herein by reference.

ITEM 6.  SELECTED FINANCIAL DATA

         Selected  financial data required by this Item are incorporated  herein
by  reference  to the  information  relating to the years 1995  through 1999 set
forth in "Summary Financial Data" on Page 56 of the 1999 Annual Report.

ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
         RESULTS OF OPERATIONS

         Information  in  response  to this Item is set  forth in  "Management's
Discussion  and Analysis of Financial  Condition and Results of  Operations"  on
Pages 32 to 36 of the 1999 Annual  Report,  which  information  is  incorporated
herein by reference.

ITEM 7A.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

         The Company uses foreign-currency  forward-exchange  contracts to hedge
forecasted  intercompany  transactions and forecasted purchases of data services
from  a  third  party  provider.   The  Company  enters  into   foreign-currency
forward-exchange  contracts  with  durations  of less than  twelve  months.  The
Company adopted SFAS No. 133, "Accounting for Derivative Instruments and Hedging
Activities,"  on January 1, 1999.  The  cumulative  effect of  adoption  was not
material  to the  consolidated  financial  statements.  Gains or  losses on such
contracts  were not material to the  consolidated  financial  statements for the
years ended December 31, 1999 and 1998. The Company does not utilize  derivative
financial instruments for trading or other speculative purposes.

         The  following  table  presents the notional  amounts,  fair values and
average   exchange   rates  of   foreign-currency   forward-exchange   contracts
outstanding at December 31, 1999 (in thousands of U.S. dollars):

                                                               Average Foreign-
                                 Notional          Fair        Currency Forward-
                                  Amounts          Value        Exchange Rates
                                ----------        -------     ------------------
        Euro                     $  5,923         $   99              .9755
        Japanese yen                  660            (24)          102.7958
        Australian dollars            109             (1)            1.5793
        Other                         154             16
        ----------------------  ---------        --------
        Total                    $  6,846         $   90
        ----------------------  ---------        --------

                                       10
<PAGE>


         At December 31, 1999, the Company had outstanding fixed-rate short-term
debt of  $95,139  (in  thousands  of U.S.  dollars)  borrowed  under its  credit
facilities. The weighted-average interest rate of this debt at December 31, 1999
was 3.32%.

         The Company had  intercompany  loans of $2,319 and $3,367 (in thousands
of U.S. dollars) denominated in U.S. dollars and Canadian dollars, respectively,
on a Colombian Peso functional currency balance sheet at December 31, 1999 which
were paid in January 2000.

ITEM 8.    FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

        See Index to Financial Statements and Schedule under Item 14 on Page 14.

ITEM 9.    CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
           FINANCIAL DISCLOSURE

        Not applicable.


                                    PART III

ITEM 10.   DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

         Information  in  response  to  this  Item  is  incorporated  herein  by
reference  to the  section  entitled  "Proposals  To Be Voted On;  Proposal  No.
1-Election of Directors" in the Company's  proxy  statement dated March 10, 2000
filed with the  Securities  and  Exchange  Commission,  except  that  "Executive
Officers of the Registrant" on Page 9 of this report responds to Item 401(b) and
(e) of Regulation S-K with respect to the Company's executive officers.

ITEM 11.   EXECUTIVE COMPENSATION

         Information  in  response  to  this  Item  is  incorporated  herein  by
reference  to the sections  entitled  "Board  Structure  and  Compensation"  and
"Compensation  of Executive  Officers" in the Company's  proxy  statement  dated
March 10, 2000 filed with the Securities and Exchange Commission.

ITEM 12.   SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

         Information  in  response  to  this  Item  is  incorporated  herein  by
reference to the section  entitled  "Common Stock  Ownership of  Management  and
Certain Beneficial Owners" in the Company's proxy statement dated March 10, 2000
filed with the Securities and Exchange Commission.

ITEM 13.   CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

         Not applicable.

                                       11
<PAGE>

                                     PART IV

ITEM 14.   EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K

              (a) List of documents filed as part of this report.
                      (1)  Financial Statements.
                           See Index to Financial Statements and Schedule
                           on Page 14.

                      (2)  Financial Statement Schedule.
                           See Index to Financial Statements and Schedule
                           on Page 14.

                      (3)  Other Financial Information.
                           Summary Financial Data.  See Index to Financial
                           Statements and Schedule on Page 14.

                      (4)  Exhibits.
                           See  Index  to  Exhibits  on  Pages  17 to 19,  which
                           indicates which Exhibits are management  contracts or
                           compensatory  plans required to be filed as Exhibits.
                           Only responsive information appearing on Pages 32
                           to 56 to Exhibit 13 is incorporated  herein by
                           reference, and no other information appearing in
                           Exhibit 13 is or shall be deemed to be filed as part
                           of this Form 10-K.

              (b) Reports on Form 8-K.
                      None.

                                       12
<PAGE>


SIGNATURES

Pursuant to the  requirements of Section 13 or 15(d) of the Securities  Exchange
Act of 1934,  the  registrant  has duly  caused  this report to be signed on its
behalf by the undersigned, thereunto duly authorized.

                                         ACNIELSEN CORPORATION
                                              (Registrant)



                                  By:        /s/ROBERT J. CHRENC
                               ------------------------------------------
                                           Robert J. Chrenc
                                  (Executive Vice President and Chief
                                          Financial Officer)


Date: March 27, 2000

         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
this  report has been  signed  below by the  following  persons on behalf of the
registrant and in the capacities and on the date indicated.


     /s/NICHOLAS L. TRIVISONNO                 /s/KAREN L. HENDRICKS*
--------------------------------------     -----------------------------------
      Nicholas L. Trivisonno                   (Karen L. Hendricks, Director)
(Chairman, Chief Executive Officer
         and Director)
   (Principal Executive Officer)

     /s/ROBERT J. CHRENC                       /s/ROBERT M. HENDRICKSON*
--------------------------------------     -----------------------------------
        Robert J. Chrenc                    (Robert M. Hendrickson, Director)
(Executive Vice President and Chief
       Financial Officer)
(Principal Financial and Accounting Officer)

     /s/MICHAEL S. GELTZEILER                  /s/ROBERT HOLLAND, JR.*
--------------------------------------     -----------------------------------
         Michael S. Geltzeiler               (Robert Holland, Jr., Director)
(Senior Vice President and Controller)

     /s/ROBERT H. BEEBY*                       /s/JOHN R. MEYER*
--------------------------------------     -----------------------------------
    (Robert H. Beeby, Director)                (John R. Meyer, Director)

     /s/MICHAEL P. CONNORS*                    /s/BRIAN B. PEMBERTON*
--------------------------------------     -----------------------------------
   (Michael P. Connors, Director)            (Brian B. Pemberton, Director)

     /s/DONALD W. GRIFFIN*                     /s/ROBERT N. THURSTON*
--------------------------------------     -----------------------------------
  (Donald W. Griffin, Director)              (Robert N. Thurston, Director)

     /s/THOMAS C. HAYS*
--------------------------------------
   (Thomas C. Hays, Director)


*By:          /s/ Ellenore O'Hanrahan
              --------------------------------------------------
              (Ellenore O'Hanrahan, attorney-in-fact)


Date: March 27, 2000


                                       13
<PAGE>


                   INDEX TO FINANCIAL STATEMENTS AND SCHEDULE

FINANCIAL STATEMENTS:

         The Company's consolidated financial statements,  the notes thereto and
the  related  report  thereon  of  Arthur  Andersen  LLP,   independent   public
accountants, for the year ended December 31, 1999 appearing on Pages 37 to 56 of
the 1999 Annual Report, are incorporated by reference into this Annual Report on
Form 10-K (see below).  The additional  financial data indicated below should be
read in conjunction with such consolidated financial statements.


                                                                Page
                                                       -------------------------
                                                          10-K      1999 Annual
                                                                       Report
                                                       ----------   ------------
    Report of Independent Public Accountants               F-6           37
    Statement of Management Responsibility
       for Financial Statements                            F-6           37
    As of December 31, 1999 and 1998:
       Consolidated Balance Sheets                         F-8           39
    For the years ended December 31, 1999, 1998 and 1997:
       Consolidated Statements of Income                   F-7           38
       Consolidated Statements of Cash Flows               F-9           40
       Consolidated Statements of Shareholders' Equity     F-10          41
       Notes to Consolidated Financial Statements          F-11          42
    Quarterly Financial Data (Unaudited) for the years
       ended December 31, 1999 and 1998                    F-23          55
    Management's Discussion and Analysis of Financial
        Condition and Results of Operations                F-1           32
    Other financial information:
        Five-year selected financial data                  F-24          56


    SCHEDULE:
       Report of Independent Public Accountants            15            --

       ACNielsen Corporation and Subsidiaries:

       II-Valuation and Qualifying Accounts for the
         years ended December 31, 1999, 1998 and 1997      16            --

         Schedules  other than the one listed  above are omitted as not required
or  inapplicable  or  because  the  required  information  is  provided  in  the
consolidated financial statements, including the notes thereto.

                                       14
<PAGE>


                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS


To the Shareholders and Board of Directors of ACNielsen Corporation:

         We  have  audited  in  accordance  with  generally   accepted  auditing
standards, the 1999, 1998 and 1997 consolidated financial statements included in
ACNielsen  Corporation's  1999 Annual Report  incorporated  by reference in this
Form 10-K, and have issued our report thereon dated February 17, 2000. Our audit
was made for the  purpose of forming an opinion on those  statements  taken as a
whole. The 1999, 1998 and 1997 schedule listed in the accompanying  index is the
responsibility  of the  Company's  management  and is presented  for purposes of
complying with the Securities and Exchange Commission's rules and is not part of
the basic financial statements. This schedule has been subjected to the auditing
procedures  applied in the audits of the basic financial  statements and, in our
opinion,  fairly states in all material  respects the financial data required to
be set forth therein in relation to the basic  financial  statements  taken as a
whole.



                                                /s/ARTHUR ANDERSEN LLP



Stamford, Connecticut
February 17, 2000

                                       15
<PAGE>
<TABLE>
                     ACNIELSEN CORPORATION AND SUBSIDIARIES

                 SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS
                for the years ended December 31, 1999, 1998, 1997
                                 (In thousands)
<CAPTION>
----------------------------------------------------    ------------------    ---------------    -----------------   --------------

                        COL. A                               COL. B               COL. C              COL. D             COL. E
----------------------------------------------------    ------------------    ---------------    -----------------   --------------
----------------------------------------------------    ------------------    ---------------    -----------------   --------------

                                                             Balance            Additions                                Balance
                                                            Beginning           Charged to                               at End
                     Description                            of Period           Operations        Deductions(a)         of Period
                                                           -----------         ------------      ---------------       -----------
ALLOWANCE FOR DOUBTFUL ACCOUNTS:
     <S>                                                     <C>                 <C>                 <C>                 <C>

     For the Year Ended December 31, 1999                    $ 13,890              $  843            $ 4,405 (b)         $ 10,328
                                                             ========            ========            =======             ========

     For the Year Ended December 31, 1998                    $ 12,114            $  4,140 (b)        $ 2,364             $ 13,890
                                                             ========            ========            =======             ========

     For the Year Ended December 31, 1997                    $ 10,847            $  2,330            $ 1,063             $ 12,114
                                                             ========            ========            =======             ========
<FN>
NOTE:    (a)  Represents primarily the charge-off of uncollectible accounts for
              which a reserve was provided.
         (b)  During 1998,  an unusually  large  reserve was provided due to the
              difficult  economic  climate  in Asia  Pacific  and  the  Emerging
              Markets. Deductions in 1999 reflect the resolution of the accounts
              for which a reserve was provided in 1998.
</FN>
</TABLE>

<TABLE>
<CAPTION>
                                                              Balance             Additions                               Balance
                                                             Beginning            Charged to                              At End
                     Description                             of Period            Operations          Deductions         Of Period
                    -------------                           -----------          ------------        ------------       -----------
ACCRUALS FOR SPECIAL CHARGES:
     <S>                                                      <C>                  <C>                 <C>              <C>

     For the Year Ended December 31, 1999
       Postemployment Benefits/Workforce Reductions           $  3,103                $   0            $  3,103              $  0
       Contractual Obligations                                   5,240                    0               1,843             3,397(d)
       Rationalize Product Lines                                   413                    0                 413                 0
       Facilities/Real Estate                                      248                    0                 248                 0
                                                              ---------              -------           ---------        ----------
                                                              $  9,004                $   0            $  5,607         $   3,397
                                                              =========              =======           =========        ==========

     For the Year Ended December 31, 1998
       Postemployment Benefits/Workforce Reductions           $ 13,200                $   0            $ 10,097         $   3,103
       Contractual Obligations                                   8,769                    0               3,529             5,240
       Rationalize Product Lines                                18,300                    0              17,887               413
       Facilities/Real Estate                                    5,300                    0               5,052               248
                                                              ---------              -------           ---------        ----------
                                                              $ 45,569                $   0            $ 36,565 (c)     $   9,004
                                                              =========              =======           =========        ==========
     For the Year Ended December 31, 1997
       Postemployment Benefits/Workforce Reductions           $  8,563             $ 12,400            $  7,763         $  13,200
       Contractual Obligations                                  30,826                    0              22,057             8,769
       Asset Revaluations                                        3,580                    0               3,580                 0
       Rationalize Product Lines                                     0               18,300                   0            18,300
       Facilities/Real Estate                                        0                5,300                   0             5,300
                                                              ---------             --------           ---------        ----------
                                                              $ 42,969             $ 36,000            $ 33,400         $  45,569
                                                              =========           ==========           =========        ==========

<FN>
NOTE:  (c)    Includes non-cash charges of $6,132 to rationalize product lines and $1,130 for consolidation of facilities.
       (d)  Represents a long-term lease obligation that will be paid through 2003.
</FN>
</TABLE>

                                       16
<PAGE>

INDEX TO EXHIBITS

  Exhibit Number
  Regulation S-K       Description
------------------    -------------
        3              Articles of Incorporation and By-laws.

                      (a)   Restated  Certificate of  Incorporation  of    *
                            the Company dated October 7, 1996
                            (incorporated   herein  by   reference   to
                            Exhibit 3.1 to the  Company's  Registration
                            Statement on Form 10,  Commission  File No.
                            001-12277 (the "Form 10")).
                      (b)   Amended and Restated By-laws of the Company    *
                            (incorporated  herein  by  reference  to
                            Exhibit 3.2 to the Form 10).

        4             Instruments Defining the Rights of Security Holders,
                      Including Indentures.

                      (a)   Rights  Agreement  dated as of October  17,    *
                            1996 between  ACNielsen Corporation  and
                            First  Chicago  Trust  Company  of New York
                            (incorporated   herein  by   reference   to
                            Exhibit 1 to the  Company's  Form 8-A filed
                            on October 18,  1996,  Commission  File No.
                            001-12277).

                      (b)   ACNielsen   Corporation  U.S.  $250,000,000    *
                            Credit  Agreement  dated as of April  15,
                            1998  (incorporated  herein by reference to
                            Exhibit  4(b)  to the  Company's  Quarterly
                            Report  on  Form  10-Q  for  the  quarterly
                            period ended June 30, 1998, Commission File
                            No. 001-12277).

        10            Material Contracts. (All of the following documents,
                      except for items (a) through (f), are management
                      contracts or compensatory plans or arrangements
                      required to be filed pursuant to Item 14(c).)

                      (a)   Distribution  Agreement dated as of October    *
                            28,  1996  among  The  Dun  & Bradstreet
                            Corporation,   Cognizant   Corporation  and
                            ACNielsen Corporation  (incorporated herein
                            by reference  to Exhibit  10(a) to the 1996
                            Form 10-K).

                      (b)   Tax  Allocation   Agreement   dated  as  of    *
                            October 28, 1996 among The Dun & Bradstreet
                            Bradstreet Corporation, Cognizant Corporation
                            and ACNielsen Corporation (incorporated
                            herein by reference to Exhibit 10(b) to the
                            1996 Form 10-K).

                      (c)   Employee  Benefits  Agreement  dated  as of    *
                            October 28, 1996 among The Dun & Bradstreet
                            Corporation, Cognizant Corporation and
                            ACNielsen Corporation (incorporated herein
                            by reference to Exhibit 10(c) to the 1996
                            Form 10-K).

                      (d)   Intellectual Property Agreement dated as of    *
                            October 28, 1996 among The Dun & Bradstreet
                            Corporation, Cognizant Corporation and
                            ACNielsen Corporation (incorporated herein
                            by reference to Exhibit 10(d) to the 1996
                            Form 10-K).


+This  exhibit  constitutes  a  management   contract,   compensatory  plan,  or
arrangement.
*Incorporated herein by reference to a previously filed document.


                                       17
<PAGE>

  Exhibit Number
  Regulation S-K       Description
------------------    -------------

                      (e)   TAM  Master  Agreement  dated as of October    *
                            28, 1996  between  Cognizant   Corporation
                            and  ACNielsen  Corporation   (incorporated
                            herein by reference to Exhibit 10(e) to the
                            1996 Form 10-K).

                      (f)   Indemnity and Joint Defense Agreement dated    *
                            as of  October  28,  1996  among The Dun &
                            Bradstreet      Corporation,      Cognizant
                            Corporation   and   ACNielsen   Corporation
                            (incorporated   herein  by   reference   to
                            Exhibit 10(f) to the 1996 Form 10-K).

                      (g)   1996  ACNielsen  Corporation   Non-Employee    +*
                            Directors'    Stock   Incentive      Plan
                            (incorporated   herein  by   reference   to
                            Exhibit  10(g) to the  Company's  Quarterly
                            Report  on  Form  10-Q  for  the  quarterly
                            period  ended  March 31,  1998,  Commission
                            File No. 001-12277).

                      (h)   1996  ACNielsen  Corporation   Non-Employee    +*
                            Directors'  Deferred  Compensation  Plan
                            (incorporated   herein  by   reference   to
                            Exhibit 10(h) to the 1996 Form 10-K).

                      (i)   1996 ACNielsen  Corporation  Key Employees'    +*
                            Stock   Incentive  Plan   (incorporated
                            herein by reference to Exhibit 10(i) to the
                            Company's Quarterly Report on Form 10-Q for
                            the quarterly  period ended March 31, 1998,
                            Commission File No. 001-12277).

                      (j)   1996 ACNielsen Corporation Replacement Plan    +*
                            for Certain  Employees  Holding The Dun &
                            Bradstreet Corporation  Equity-Based Awards
                            (incorporated   herein  by   reference   to
                            Exhibit 10(j) to the 1996 Form 10-K).

                      (k)   1996 ACNielsen Corporation Senior Executive    +*
                            Incentive Plan   (incorporated  herein by
                            reference to Exhibit 10(k) to the 1996 Form
                            10-K).

                      (l)   1996   ACNielsen   Corporation   Management    +*
                            Incentive   Bonus  Plan    (incorporated
                            herein by reference to Exhibit 10(l) to the
                            1996 Form 10-K).

                      (m)   ACNielsen     Corporation      Supplemental    +*
                            Executive  Retirement Plan  (incorporated
                            herein by reference to Exhibit 10(m) to the
                            1996 Form 10-K).

                      (n)   ACNielsen  Corporation  Retirement  Benefit    +*
                            Excess  Plan  (incorporated   herein  by
                            reference to Exhibit 10(n) to the 1996 Form
                            10-K).

                      (o)   ACNielsen  Corporation Executive Transition    +*
                            Plan  (incorporated   herein by reference
                            to Exhibit 10(o) to the 1996 Form 10-K).

                      (p)   Form   of   Change-in-Control    Agreements    +*
                            (incorporated  herein  by  reference  to
                            Exhibit 10(p) to the 1996 Form 10-K).

                      (q)   Form of  Option  Agreement  under  the 1996    +
                            ACNielsen   Corporation  Key  Employees'
                            Stock Incentive Plan (filed herewith).

                      (r)   Form of LSAR Agreement (incorporated herein    +*
                            by  reference  to  Exhibit  10(r) to the
                            1996 Form 10-K).


+This  exhibit  constitutes  a  management   contract,   compensatory  plan,  or
arrangement.
*Incorporated herein by reference to a previously filed document.


                                       18
<PAGE>

  Exhibit Number
  Regulation S-K       Description
------------------    -------------

                      (s)   Form   of   Directors'   Restricted   Stock    +*
                            Agreement   (incorporated    herein  by
                            reference to Exhibit 10(s) to the 1996 Form
                            10-K).

                      (t)   Form of  Option  Agreement  under  the 1996    +*
                            ACNielsen     Corporation      Non-Employee
                            Directors'     Stock     Incentive     Plan
                            (incorporated   herein  by   reference   to
                            Exhibit 10(t) to the 1998 Form 10-K).

                      (u)   ACNielsen Corporation Deferred Compensation    +*
                            Plan (incorporated herein by reference to
                            Exhibit 4.1 to the Company's Form S-8 filed
                            on February 25, 2000, Commission File No.
                            333-31152).

                      (v)   Letter  Agreement  dated  December 16, 1999    +
                            between ACNielsen  Corporation and Robert J
                            Lievense (filed herewith).

        13            Annual Report to Security Holders (filed herewith).

                            1999 Annual Report (pages 32 to 56)

                            Only  responsive  information  appearing on
                            Pages   32   to  56   to   Exhibit   13  is
                            incorporated  herein by  reference,  and no
                            other  information  appearing in Exhibit 13
                            is or shall be  deemed  to be filed as part
                            of this Form 10-K.

        21            Subsidiaries of the Registrant (filed herewith).

                            List of Active Subsidiaries as of January 31, 2000

        23            Consents of Experts and Counsel (filed herewith).

                            Consent of Arthur Andersen LLP

        24            Power of Attorney (filed herewith).

                            Powers of Attorney dated February 17, 2000

        27            Financial Data Schedule (filed herewith).

        99            Other Exhibits
                      (a)   Letter of Undertaking dated June 29, 1998      *
                            from the New Dun & Bradstreet Corporation
                            to Cognizant Corporation and ACNielsen
                            Corporation  (incorporated  herein by
                            reference to Exhibit 99(a) to the Company's
                            Quarterly Report on Form 10-Q for the
                            quarterly period ended June 30, 1998,
                            Commission File No. 001-12277).

                      (b)   Letter of  Undertaking  dated June 29, 1998    *
                            from IMS Health Incorporated to The Dun &
                            Bradstreet    Corporation   and   ACNielsen
                            Corporation (incorporated herein by
                            reference to Exhibit 99(b) to the Company's
                            Quarterly  Report  on  Form  10-Q  for  the
                            quarterly   period  ended  June  30,  1998
                            Commission File No. 001-12277).

                      (c)   Letter of Undertaking  dated July 16, 1999
                            from Gartner Group, Inc. to R.H. Donnelley
                            Corporation  and ACNielsen  Corporation
                            (filed herewith).


+This  exhibit  constitutes  a  management   contract,   compensatory  plan,  or
arrangement.
*Incorporated herein by reference to a previously filed document.

                                       19
<PAGE>