UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                    FORM 10-Q/A


[x]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES
      EXCHANGE ACT OF 1934


      For the quarterly period ended              March 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  0-14007
                           ---------



                        MCNEIL REAL ESTATE FUND XX, L.P.
--------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)



         California                           33-0050225
--------------------------------------------------------------------------------
(State or other jurisdiction of              (I.R.S. Employer
incorporation or organization)                Identification No.)



             13760 Noel Road, Suite 600, LB70, Dallas, Texas, 75240
--------------------------------------------------------------------------------
               (Address of principal executive offices) (Zip code)



Registrant's telephone number, including area code          (972) 448-5800
                                                   -----------------------------



Indicate  by check  mark  whether  the  registrant,  (1) has filed  all  reports
required to be filed 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
                                      ---  ---
<PAGE>
                          PART I. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS
------- --------------------

                        MCNEIL REAL ESTATE FUND XX, L.P.

                                 BALANCE SHEETS
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                                           March 31,         December 31,
                                                                             1999                1998
                                                                         -----------         ------------
ASSETS
------

Real estate investments:
<S>                                                                      <C>                 <C>        
   Land .........................................................        $   392,000         $   392,000
   Buildings and improvements ...................................          3,988,288           3,981,407
                                                                         -----------         -----------
                                                                           4,380,288           4,373,407
   Less:  Accumulated depreciation ..............................         (1,583,113)         (1,525,208)
                                                                         -----------         -----------
                                                                           2,797,175           2,848,199

Cash and cash equivalents .......................................          1,518,836           3,070,785
Cash segregated for security deposits ...........................             33,936              28,773
Accounts receivable .............................................              5,252               6,603
Escrow deposits .................................................             72,715             180,267
Deferred borrowing costs, net of accumulated
   amortization of $80,397 and $76,154 at
   March 31, 1999 and December 31, 1998, respectively ...........             81,097              85,340
Prepaid expenses and other assets ...............................              5,500               5,500
                                                                         -----------         -----------
                                                                         $ 4,514,511         $ 6,225,467
                                                                         ===========         ===========

LIABILITIES AND PARTNERS' EQUITY (DEFICIT)
------------------------------------------

Mortgage note payable, net ......................................        $ 2,586,742         $ 2,613,312
Accounts payable and other accrued expenses .....................             67,132              52,848
Accrued property taxes ..........................................             35,542             142,490
Payable to affiliates ...........................................            277,526             376,849
Security deposits and deferred rental revenue ...................             26,165              27,702
                                                                         -----------         -----------
                                                                           2,993,107           3,213,201
                                                                         -----------         -----------

Partners' equity (deficit):
   Limited partners - 60,000 limited partnership units
     authorized;  49,512 limited partnership units issued
     and outstanding at March 31, 1999 and December
     31, 1998 ...................................................          1,805,190           3,296,145
   General Partner ..............................................           (283,786)           (283,879)
                                                                         -----------         -----------
                                                                           1,521,404           3,012,266
                                                                         -----------         -----------
                                                                         $ 4,514,511         $ 6,225,467
                                                                         ===========         ===========
</TABLE>

The  financial  information  included  herein has been  prepared  by  management
without audit by independent public accountants.

                 See accompanying notes to financial statements.
<PAGE>
                        McNEIL REAL ESTATE FUND XX, L.P.

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)

<TABLE>
<CAPTION>

                                                                       Three Months Ended
                                                                           March 31,
                                                                   ------------------------
                                                                     1999            1998
                                                                   --------        --------
Revenue:
<S>                                                                <C>             <C>     
   Rental revenue .........................................        $326,553        $337,688
   Interest income on mortgage loan investments ...........              --          69,496
   Interest income on mortgage loan investments -
     affiliate ............................................              --         108,214
   Other interest income ..................................          34,936          22,163
                                                                   --------        --------
     Total revenue ........................................         361,489         537,561
                                                                   --------        --------

Expenses:
   Interest ...............................................          60,394          61,304
   Depreciation ...........................................          57,905          59,445
   Property taxes .........................................          35,826          36,892
   Personnel costs ........................................          38,719          40,797
   Utilities ..............................................          19,181          20,225
   Repairs and maintenance ................................          26,775          28,876
   Property management fees - affiliates ..................          15,819          14,994
   Other property operating expenses ......................          15,625          20,709
   General and administrative .............................          37,614          48,435
   General and administrative - affiliates ................          44,292          64,400
                                                                   --------        --------
     Total expenses .......................................         352,150         396,077
                                                                   --------        --------

Net income ................................................        $  9,339        $141,484
                                                                   ========        ========


Net income allocable to limited partners ..................        $  9,246        $140,069
Net income allocable to General Partner ...................              93           1,415
                                                                   --------        --------
Net income ................................................        $  9,339        $141,484
                                                                   ========        ========


Net income per limited partnership unit ...................        $    .19        $   2.83
                                                                   ========        ========

Distributions per limited partnership unit ................        $  30.30        $  29.94
                                                                   ========        ========
</TABLE>


The  financial  information  included  herein has been  prepared  by  management
without audit by independent public accountants.

                 See accompanying notes to financial statements.
<PAGE>
                        MCNEIL REAL ESTATE FUND XX, L.P.

                    STATEMENTS OF PARTNERS' EQUITY (DEFICIT)
                                   (Unaudited)

               For the Three Months Ended March 31, 1999 and 1998


<TABLE>
<CAPTION>
                                                                                             Total
                                                   General              Limited            Partners'
                                                   Partner             Partners         Equity (Deficit)
                                                 ------------        ------------       ----------------
<S>                                              <C>                 <C>                 <C>        
Balance at December 31, 1997 ............        $  (296,465)        $ 9,282,684         $ 8,986,219

Net income ..............................              1,415             140,069             141,484

Distributions to limited partners........                 --          (1,482,316)         (1,482,316)
                                                 -----------         -----------         -----------

Balance at March 31, 1998 ...............        $  (295,050)        $ 7,940,437         $ 7,645,387
                                                 ===========         ===========         ===========


Balance at December 31, 1998 ............        $  (283,879)        $ 3,296,145         $ 3,012,266

Net income ..............................                 93               9,246               9,339

Distributions to limited partners .......                 --          (1,500,201)         (1,500,201)
                                                 -----------         -----------         -----------

Balance at March 31, 1999 ...............        $  (283,786)        $ 1,805,190         $ 1,521,404
                                                 ===========         ===========         ===========
</TABLE>



The  financial  information  included  herein has been  prepared  by  management
without audit by independent public accountants.

                 See accompanying notes to financial statements.
<PAGE>
                        MCNEIL REAL ESTATE FUND XX, L.P.

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)

                Increase (Decrease) in Cash and Cash Equivalents
<TABLE>
<CAPTION>
                                                                     Three Months Ended
                                                                           March 31,
                                                               --------------------------------
                                                                   1999               1998
                                                               ------------        ------------

Cash flows from operating activities:
<S>                                                            <C>                 <C>        
   Cash received from tenants .........................        $   322,930         $   364,529
   Cash paid to suppliers .............................           (136,357)           (173,329)
   Cash paid to affiliates ............................           (159,434)            (15,262)
   Interest received ..................................             34,936              90,074
   Interest received from affiliate ...................                 --             108,131
   Interest paid ......................................            (41,526)            (55,301)
   Property taxes paid ................................               (284)               (281)
   Property taxes escrowed ............................            (36,329)            (46,800)
                                                               -----------         -----------
Net cash provided by (used in) operating
   activities .........................................            (16,064)            271,761
                                                               -----------         -----------

Cash flows from investing activities:
   Additions to real estate investments ...............             (6,881)             (6,021)
   Collection of principal on mortgage loan
     investments ......................................                 --              34,465
   Collection of principal on mortgage loan
     investments - affiliate ..........................                 --               4,089
                                                               -----------         -----------
   Net cash provided by (used in) investing
      activities ......................................             (6,881)             32,533
                                                               -----------         -----------

Cash flows from financing activities:
   Principal payments on mortgage note payable.........            (28,803)            (15,029)
   Distributions to limited partners ..................         (1,500,201)         (1,482,316)
                                                               -----------         -----------
Net cash used in financing activities .................         (1,529,004)         (1,497,345)
                                                               -----------         -----------

Net decrease in cash and cash .equivalents ............         (1,551,949)         (1,193,051)

Cash and cash equivalents at beginning of
   period .............................................          3,070,785           1,824,293
                                                               -----------         -----------

Cash and cash equivalents at end of period ............        $ 1,518,836         $   631,242
                                                               ===========         ===========
</TABLE>


The  financial  information  included  herein has been  prepared  by  management
without audit by independent public accountants.

                 See accompanying notes to financial statements.
<PAGE>
                        MCNEIL REAL ESTATE FUND XX, L.P.

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)

              Reconciliation of Net Income to Net Cash Provided by
                         (Used In) Operating Activities

<TABLE>
<CAPTION>
                                                                  Three Months Ended
                                                                       March 31,
                                                             ---------------------------
                                                                1999              1998
                                                             ----------        ---------
<S>                                                          <C>               <C>      
Net income ..........................................        $   9,339         $ 141,484
                                                             ---------         ---------

Adjustments to reconcile net income to
   net cash provided by (used in) operating
   activities:
   Depreciation .....................................           57,905            59,445
   Amortization of deferred borrowing costs .........            4,243             3,983
   Amortization of discount on mortgage note
     payable ........................................            2,233             2,122
   Changes in assets and liabilities:
     Cash segregated for security deposits ..........           (5,163)           (4,506)
     Accounts receivable ............................            1,351            33,191
     Escrow deposits ................................          107,552           (42,735)
     Accounts payable and other accrued
       expenses .....................................           14,284           (18,859)
     Accrued property taxes .........................         (106,948)           36,611
     Payable to affiliates ..........................          (99,323)           64,132
     Deferred revenue ...............................               --            (1,656)
     Security deposits and deferred rental
       revenue ......................................           (1,537)           (1,451)
                                                             ---------         ---------

       Total adjustments ............................          (25,403)          130,277
                                                             ---------         ---------

Net cash provided by (used in) operating
      activities ....................................        $ (16,064)        $ 271,761
                                                             =========         =========
</TABLE>


The  financial  information  included  herein has been  prepared  by  management
without audit by independent public accountants.

                 See accompanying notes to financial statements.
<PAGE>
                        MCNEIL REAL ESTATE FUND XX, L.P.

                          Notes to Financial Statements
                                 March 31, 1999
                                   (Unaudited)

NOTE 1.
-------

McNeil  Real  Estate  Fund  XX,  L.P.  (the  "Partnership"),  formerly  known as
Southmark  Income  Investors,  Ltd., was organized on July 19, 1984 as a limited
partnership  under the  provisions of the  California  Revised  Uniform  Limited
Partnership Act. The general partner of the Partnership is McNeil Partners, L.P.
(the "General Partner"), a Delaware limited partnership,  an affiliate of Robert
A. McNeil  ("McNeil").  The principal  place of business for the Partnership and
the General Partner is 13760 Noel Road, Suite 600, Dallas, Texas 75240.

In the opinion of management,  the financial  statements reflect all adjustments
necessary for a fair  presentation of the Partnership's  financial  position and
results  of  operations.  All  adjustments  were of a normal  recurring  nature.
However, the results of operations for the three months ended March 31, 1999 are
not  necessarily  indicative  of the results to be expected  for the year ending
December 31, 1999.

NOTE 2.
-------

The  financial  statements  should  be read in  conjunction  with the  financial
statements  contained in the  Partnership's  Annual  Report on Form 10-K for the
year  ended  December  31,  1998,  and the  notes  thereto,  as  filed  with the
Securities and Exchange  Commission,  which is available upon request by writing
to McNeil Real Estate Fund XX, L.P.,  c/o McNeil Real Estate  Management,  Inc.,
Investor Services, 13760 Noel Road, Suite 600, LB70, Dallas, Texas 75240.

NOTE 3.
-------

The  Partnership  pays property  management fees equal to 5% of the gross rental
receipts for its properties to McNeil Real Estate Management,  Inc.  ("McREMI"),
an affiliate of the General Partner, for providing property management services.

Under the terms of its partnership agreement, the Partnership pays a disposition
fee to an  affiliate  of the General  Partner  equal up to 3% of the gross sales
price  for  brokerage  services  performed  in  connection  with the sale of the
Partnership's  properties,  provided,  however,  that in no event shall all real
estate  commissions  (including the disposition  fee) paid to all persons exceed
the amount customarily charged in similar arms-length  transactions.  The fee is
due and payable at the time the sale closes.  The Partnership  incurred $124,500
of such  fees  during  1997  in  connection  with  the  sale of 1130  Sacramento
Condominiums.  This amount represents 2.65% of the gross sales price. These fees
were  paid in the  first  quarter  of 1999  and  were  included  in  payable  to
affiliates on the Balance Sheet at December 31, 1998.


<PAGE>
The  Partnership  reimburses  McREMI  for  its  costs,  including  overhead,  of
administering the Partnership's affairs.

The  Partnership  is paying an asset  management  fee  which is  payable  to the
General  Partner.  Through 1999, the asset management fee is calculated as 1% of
the  Partnership's  tangible asset value.  Tangible asset value is determined by
using the greater of (i) an amount calculated by applying a capitalization  rate
of 9% to the annualized net operating income of each property or (ii) a value of
$10,000 per apartment unit to arrive at the property  tangible asset value.  The
property  tangible  asset  value is then  added to the book  value of all  other
assets excluding intangible items. The fee percentage decreases to .75% in 2000,
 .50% in 2001 and .25% thereafter. Total accrued but unpaid asset management fees
of $160,863 and  $148,528  were  outstanding  at March 31, 1999 and December 31,
1998, respectively.

Compensation  and  reimbursements  paid to or  accrued  for the  benefit  of the
General Partner or its affiliates are as follows:

                                                          Three Months Ended
                                                               March 31,
                                                      -------------------------
                                                         1999           1998
                                                      ----------     ----------

Property management fees.......................       $   15,819     $   14,994
Charged to general and administrative -
   affiliates:
   Partnership administration..................           21,480         25,167
   Asset management fee........................           22,812         39,233
                                                       ---------      ---------
                                                      $   60,111     $   79,394
                                                       =========      =========

Payable  to  affiliates  at March  31,  1999 and  December  31,  1998  consisted
primarily of unpaid  property  management  fees,  disposition  fees (1998 only),
Partnership general and administrative expenses and asset management fees and is
due and payable from current operations.

NOTE 4.
-------

The  Partnership's  mortgage loan  investments - affiliate were secured by first
and second  liens on Fort Meigs  Plaza  Shopping  Center,  which was owned by an
affiliate of the General  Partner.  On April 20, 1998, Fort Meigs Plaza was sold
to a  non-affiliate  for a gross sales price of $3.8  million.  The  Partnership
received  $3,615,353  as  payment  in  full  for  both  principal  and  interest
receivable on the loans,  which represented the available cash proceeds from the
sale of the property.

NOTE 5.
-------

The  mortgage  loan  investment  secured by  Idlewood  Nursing  Home  matured in
February  1998. On May 1, 1998, the  Partnership  received $2.4 million from the
borrower as payment in full for both  principal  and interest  receivable on the
loan (the actual balance of the loan was greater than the book value). Since the
Partnership  owned an 83%  participation  interest in the note,  $408,000 of the
$2.4 million settlement was paid to the owner of the remaining 17% of the note.

<PAGE>
NOTE 6.
-------

On August 20, 1998, the Partnership  received  $2,541,572 as payment in full for
both principal and interest  receivable on the mortgage loan investment  secured
by  Lakeland  Nursing  Home.  Since the  Partnership  owned a 90%  participation
interest  in the  note,  $254,157  of the  payoff  was paid to the  owner of the
remaining 10% of the note. Of the $2,287,415 net proceeds  received,  $2,249,181
was applied to the  principal  balance of the loan and the remaining was applied
to accrued interest receivable.

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
-------  ---------------------------------------------------------------
         RESULTS OF OPERATIONS
         ---------------------

FINANCIAL CONDITION
-------------------

There has been no  significant  change in the  operations  of  Sterling  Springs
Apartments,  the Partnership's  only property.  The Partnership's  mortgage loan
investments  - affiliate  secured by Fort Meigs Plaza were repaid in April 1998.
The Partnerships two mortgage loan investments  secured by Idlewood Nursing Home
and Lakeland Nursing Home were repaid in May 1998 and August 1998, respectively.

The Partnership reported net income of $9,339 for the first three months of 1999
as  compared  to  $141,484  for the same  period in 1998.  Revenues in the first
quarter of 1999  decreased  to $361,489  from  $537,561 in the first  quarter of
1998,  while  expenses were $352,150 in the first quarter of 1999 as compared to
$396,077 in the first quarter of 1998.

Net cash used in  operating  activities  was $16,064 for the three  months ended
March 31, 1999. The Partnership expended $6,881 for capital  improvements,  made
$28,803 in  principal  payments on its  mortgage  note  payable and  distributed
$1,500,201 to the limited partners. Cash and cash equivalents totaled $1,518,836
at March 31, 1999, a net decrease of $1,551,949 from the balance at December 31,
1998.

RESULTS OF OPERATIONS
---------------------

Revenue:

Total revenue decreased by $176,072 for the three months ended March 31, 1999 as
compared to the same period in 1998.  The  decrease was mainly due to a decrease
in interest income on mortgage loan  investments and mortgage loan investments -
affiliate,  partially  offset  by an  increase  in  other  interest  income,  as
discussed below.

Interest  income on mortgage  loan  investments  for the quarter ended March 31,
1999  decreased  by $69,496 in relation to the  comparable  period in 1998.  The
decrease was due to the Lakeland  Nursing Home  mortgage loan  investment  being
paid off by the  borrower in August 1998.  Although  the  Idlewood  Nursing Home
mortgage loan  investment  was also paid off in 1998, no interest was accrued on
this loan in 1998.




<PAGE>
Interest income on mortgage loan  investments - affiliate  decreased by $108,214
for the first three  months of 1999 as compared to the same period in 1998.  The
decrease  was due to both of the Fort  Meigs  Plaza  loans  being  repaid by the
affiliate borrower in April 1998.

Other interest income  increased by $12,773 for the three months ended March 31,
1999 as  compared  to the  same  period  in  1998,  due to an  increase  in cash
available for short-term  investment.  The Partnership held  approximately  $1.5
million  of  cash  and  cash  equivalents  at  March  31,  1999 as  compared  to
approximately $0.6 million at March 31, 1998.

Expenses:

Total expenses decreased by $43,927 for the three months ended March 31, 1999 as
compared to the same period in 1998. The decrease was mainly due to decreases in
other  property  operating  expenses,  general and  administrative  expenses and
general and administrative - affiliates, as discussed below.

Other  property  operating  expenses for the first quarter of 1999  decreased by
$5,084 as compared  to the first  quarter of the prior year.  The  decrease  was
mainly due to a decrease in bad debts and property  insurance  costs at Sterling
Springs Apartments.

General and  administrative  expenses  decreased  by $10,821 for the first three
months of 1999 in relation to the same period in 1998.  The  decrease was mainly
due to a greater  amount of costs  incurred in 1998 to explore  alternatives  to
maximize the value of the Partnership (see Liquidity and Capital Resources).

General and  administrative  expenses - affiliates  decreased by $20,108 for the
quarter ended March 31, 1999 in relation to the same period in 1998,  mainly due
to a decrease in asset management fees. The decrease was due to a decline in the
tangible asset value of the Partnership, on which the fees are based, due to the
payoff  of  the  Partnership's  mortgage  loan  investments  and  mortgage  loan
investments - affiliate in 1998.

LIQUIDITY AND CAPITAL RESOURCES
-------------------------------

The Partnership used $16,064 of cash in operating activities for the first three
months of 1999 as compared to $271,761  generated  during the first three months
of 1998.  The  decrease  in 1999 was  partially  due to a decrease  in  interest
received  from  an  affiliate  relating  to the  Fort  Meigs  Plaza  loans  (see
discussion  of decrease  in  interest  income on  mortgage  loan  investments  -
affiliate,  above).  In addition,  the Partnership  paid $124,500 of disposition
fees to the General Partner in the first quarter of 1999 as discussed in Note 3.

In the  first  three  months  of 1998,  the  Partnership  collected  $34,465  of
principal on mortgage loan  investments.  No such  collections were made in 1999
since the  Idlewood  Nursing  Home loan was repaid in May 1998 and the  Lakeland
Nursing Home loan was repaid in August 1998.

The Partnership  distributed  $1,500,201 and $1,482,316 to the limited  partners
during the three months ended March 31, 1999 and 1998, respectively.






<PAGE>
Short-term liquidity:

At March 31, 1999, the Partnership held cash and cash equivalents of $1,518,836.
This  balance   provides  a  reasonable   level  of  working   capital  for  the
Partnership's immediate needs in operating its remaining property.

In 1999,  operation  of  Sterling  Springs  Apartments  is  expected  to provide
sufficient  positive cash flow for normal  operations.  Management  will perform
routine  repairs and  maintenance  on the  property to preserve  and enhance its
value  and   competitiveness   in  the  market.  The  Partnership  has  budgeted
approximately  $74,000 for  capital  improvements  to Sterling  Springs in 1999,
which is expected to be funded from operations of the property.

Additional efforts to maintain and improve  Partnership  liquidity have included
continued attention to property management activities. The objective has been to
obtain maximum  occupancy  rates while holding  expenses to levels  necessary to
maximize  cash flows.  The  Partnership  has made  capital  expenditures  on its
property where  improvements were expected to increase the  competitiveness  and
marketability of the property.

Long-term liquidity:

The  Partnership's  property,  Sterling Springs  Apartments,  is encumbered with
mortgage debt. The mortgage is not due until 2003.

While the outlook for  maintenance of adequate levels of liquidity is favorable,
should  operations  deteriorate and present cash resources be  insufficient  for
current needs,  the Partnership  would require other sources of working capital.
No such sources have been identified.  The Partnership has no established  lines
of  credit  from  outside  sources.  Other  possible  actions  to  resolve  cash
deficiencies  include  refinancings,  deferral  of capital  expenditures  on the
Partnership's  property except where  improvements  are expected to increase the
competitiveness  and  marketability  of the property,  arranging  financing from
affiliates or the ultimate sale of the property.

As previously announced, the Partnership has retained PaineWebber,  Incorporated
as its exclusive financial advisor to explore alternatives to maximize the value
of the  Partnership,  including,  without  limitation,  a  transaction  in which
limited partnership interests in the Partnership are converted into cash. During
the last full week of March,  the Partnership  entered into a 45 day exclusivity
agreement  with a  well-financed  bidder with whom it had commenced  discussions
with respect to a sale  transaction.  The  Partnership  and such party have made
significant  progress in negotiating the terms of a proposed transaction and are
continuing to have intensive discussions with respect to a transaction. In light
on these continuing  negotiations,  the exclusivity  agreement has been extended
for an  additional  21 days until June 4, 1999.  It is possible that the General
Partner  and its  affiliates  will  receive  non-cash  consideration  for  their
ownership  interests in connection  with any such  transaction.  There can be no
assurance  regarding  whether any such  agreement  will be reached nor the terms
thereof.







<PAGE>
Forward-Looking Information:

Within this document,  certain  statements are made as to the expected occupancy
trends,  financial  condition,  results  of  operations,  and cash  flows of the
Partnership  for  periods  after March 31,  1999.  All of these  statements  are
forward-looking  statements  made pursuant to the safe harbor  provisions of the
Private  Securities  Litigation  Reform Act of 1995.  These  statements  are not
historical  and  involve  risks  and  uncertainties.  The  Partnership's  actual
occupancy trends, financial condition, results of operations, and cash flows for
future  periods may differ  materially  due to several  factors.  These  factors
include,  but are not limited to, the  Partnership's  ability to control  costs,
make necessary  capital  improvements,  negotiate the sale or refinancing of its
property,  collect  payments  on its  mortgage  loan  investment  and respond to
changing economic and competitive factors.

YEAR 2000 DISCLOSURE
--------------------

State of readiness
------------------

The year 2000 problem is the result of computer programs being written using two
digits rather than four to define the  applicable  year.  Any programs that have
time-sensitive  software may recognize a date using "00" as the year 1900 rather
than  the  year  2000.   This  could   result  in  major   systems   failure  or
miscalculations.

Management has assessed its  information  technology  ("IT")  infrastructure  to
identify  any systems  that could be affected by the year 2000  problem.  The IT
used by the  Partnership  for  financial  reporting and  significant  accounting
functions was made year 2000 compliant  during recent systems  conversions.  The
software  utilized for these  functions  is licensed by third party  vendors who
have warranted that their systems are year 2000 compliant.

Management  is  in  the  process  of  evaluating  the  mechanical  and  embedded
technological systems at the various properties.  Management has inventoried all
such systems and queried suppliers,  vendors and manufacturers to determine year
2000  compliance.  Based on this review,  management  believes these systems are
substantially compliant. In circumstances of non-compliance management will work
with the vendor to remedy the problem or seek alternative  suppliers who will be
in compliance.  Management believes that the remediation of any outstanding year
2000  conversion  issues  will not have a  material  or  adverse  effect  on the
Partnership's operations.  However, no estimates can be made as to the potential
adverse impact  resulting from the failure of third party service  providers and
vendors to be year 2000 compliant.

Cost
----

The cost of IT and  embedded  technology  systems  testing  and  upgrades is not
expected to be material to the Partnership. Because all the IT systems have been
upgraded  over the last three years,  all such systems were  compliant,  or made
compliant at no additional cost by third party vendors.  Management  anticipates
the costs of assessing,  testing, and if necessary replacing embedded technology
components will be less than $50,000.  Such costs will be funded from operations
of the Partnership.

<PAGE>
Risks
-----

Ultimately,  the potential impact of the year 2000 issue will depend not only on
the corrective measures the Partnership undertakes, but also on the way in which
the year 2000 issue is  addressed  by  government  agencies  and  entities  that
provide services or supplies to the  Partnership.  Management has not determined
the most likely worst case scenario to the  Partnership.  As management  studies
the findings of its property  systems  assessment and testing,  management  will
develop  a better  understanding  of what  would  be the  worst  case  scenario.
Management  believes  that  progress  on all  areas is  proceeding  and that the
Partnership  will  experience  no  adverse  effect  as a result of the year 2000
issue. However, there is no assurance that this will be the case.

Contingency plans
-----------------

Management  is  developing  contingency  plans to  address  potential  year 2000
non-compliance of IT and embedded technology  systems.  Management believes that
failure of any IT system could have an adverse  impact on  operations.  However,
management  believes  that  alternative  systems  are  available  that  could be
utilized to minimize  such impact.  Management  believes that any failure in the
embedded  technology  systems  could have an adverse  impact on that  property's
performance.  Management  will assess these risks and develop  plans to mitigate
possible failures by July 1999.

                           PART II. OTHER INFORMATION

ITEM 1.    LEGAL PROCEEDINGS
-------    -----------------

James F.  Schofield,  Gerald C. Gillett,  Donna S. Gillett,  Jeffrey  Homburger,
Elizabeth Jung,  Robert Lewis, and Warren Heller et al. v. McNeil Partners L.P.,
McNeil Investors,  Inc., McNeil Real Estate Management,  Inc., Robert A. McNeil,
Carole J. McNeil,  McNeil Pacific  Investors Fund 1972, Ltd., McNeil Real Estate
Fund IX,  Ltd.,  McNeil Real  Estate  Fund X, Ltd.,  McNeil Real Estate Fund XI,
Ltd.,  McNeil  Real Estate Fund XII,  Ltd.,  McNeil Real Estate Fund XIV,  Ltd.,
McNeil Real Estate Fund XV, Ltd.,  McNeil Real Estate Fund XX, L.P., McNeil Real
Estate Fund XXI, L.P.,  McNeil Real Estate Fund XXII,  L.P.,  McNeil Real Estate
Fund XXIII,  L.P.,  McNeil Real Estate Fund XXIV, L.P.,  McNeil Real Estate Fund
XXV,  L.P.,  McNeil  Real Estate  Fund XXVI,  L.P.,  and McNeil Real Estate Fund
XXVII,  L.P., Hearth Hollow  Associates,  McNeil Midwest  Properties I, L.P. and
Regency North Associates,  L.P., - Superior Court of the State of California for
the  County of Los  Angeles,  Case No.  BC133799  (Class and  Derivative  Action
Complaint).

The action involves  purported  class and derivative  actions brought by limited
partners  of each  of the  limited  partnerships  that  were  named  as  nominal
defendants as listed above (the  "Partnerships").  Plaintiffs allege that McNeil
Investors, Inc., its affiliate McNeil Real Estate Management,  Inc. and three of
their senior officers and/or directors (collectively, the "Defendants") breached
their  fiduciary  duties and certain  obligations  under the respective  Amended
Partnership  Agreement.  Plaintiffs  allege that  Defendants  have rendered such
Units highly illiquid and  artificially  depressed the prices that are available
for Units on the resale market.  Plaintiffs also allege that Defendants  engaged
in a course of conduct to prevent the  acquisition  of Units by an  affiliate of
Carl  Icahn  by  disseminating  purportedly  false,  misleading  and  inadequate
information.  Plaintiffs  further allege that Defendants  acted to advance their
own personal  interests at the expense of the Partnerships'  public unit holders
by failing to sell Partnership  properties and failing to make  distributions to
unitholders.
<PAGE>
On December 16, 1996, the Plaintiffs filed a consolidated and amended complaint.
Plaintiffs  are suing for breach of  fiduciary  duty,  breach of contract and an
accounting,  alleging,  among other things, that the management fees paid to the
McNeil affiliates over the last six years are excessive,  that these fees should
be reduced retroactively and that the respective Amended Partnership  Agreements
governing the Partnerships are invalid.

Defendants  filed a demurrer to the  consolidated  and amended  complaint  and a
motion to strike on February 14, 1997,  seeking to dismiss the  consolidated and
amended complaint in all respects.  A hearing on Defendant's demurrer and motion
to strike  was held on May 5,  1997.  The Court  granted  Defendants'  demurrer,
dismissing  the  consolidated  and  amended  complaint  with leave to amend.  On
October  31,  1997,  the  Plaintiffs  filed a second  consolidated  and  amended
complaint. The case was stayed pending settlement discussions.  A Stipulation of
Settlement dated September 15, 1998 has been signed by the parties.  Preliminary
Court  approval was received on October 6, 1998. A hearing for Final Approval of
Settlement,  initially  scheduled for December 17, 1998,  has been  continued to
July 2, 1999.

Because McNeil Real Estate Fund XXIII,  L.P., Hearth Hollow  Associates,  McNeil
Midwest  Properties I, L.P. and Regency North Associates,  L.P. would be part of
the  transaction  contemplated  in the settlement  and Plaintiffs  claim that an
effort should be made to sell the McNeil Partnerships,  Plaintiffs have included
allegations with respect to McNeil Real Estate Fund XXIII,  L.P.,  Hearth Hollow
Associates, McNeil Midwest Properties I, L.P. and Regency North Associates, L.P.
in the third consolidated and amended complaint.

Plaintiff's  counsel  intends  to seek an  order  awarding  attorney's  fees and
reimbursements  of their  out-of-pocket  expenses.  The  amount of such award is
undeterminable  until  final  approval  is  received  from the  court.  Fees and
expenses shall be allocated amongst the Partnerships on a pro rata basis,  based
upon  tangible  asset value of each such  partnership,  less total  liabilities,
calculated in accordance with the Amended Partnership Agreements for the quarter
most recently ended.


<PAGE>

ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K
-------  --------------------------------

(a)      Exhibits.

         Exhibit
         Number                    Document Description
         -------                   --------------------

         4.                        Amended and  Restated   Limited   Partnership
                                   Agreement dated March 30, 1992. (Incorporated
                                   by reference to  the  Current  Report  of the
                                   registrant on  Form 8-K dated March 30, 1992,
                                   as filed on April 10, 1992).

         11.                       Statement   regarding   computation  of   Net
                                   Income  per  Limited  Partnership  Unit:  Net
                                   income  per  limited   partnership  unit   is
                                   computed  by dividing net income allocated to
                                   the limited  partners by the weighted average
                                   number   of   limited    partnership    units
                                   outstanding.  Per unit  information has  been
                                   computed based  on 49,512 limited partnership
                                   units outstanding in 1999 and 1998.

         27.                       Financial Data Schedule for the quarter ended
                                   March 31, 1999.

(b)       Reports on Form 8-K.  There were no reports  on  Form 8-K filed during
          the quarter ended March 31, 1999.

<PAGE>
                        MCNEIL REAL ESTATE FUND XX, L.P.

                                   SIGNATURES

Pursuant  to the  requirements  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:



                           McNEIL REAL ESTATE FUND XX, L.P.

                           By:  McNeil Partners, L.P., General Partner

                                By: McNeil Investors, Inc., General Partner


May 18, 1999                    By: /s/  Ron K. Taylor
--------------                     ---------------------------------------------
Date                                Ron K. Taylor
                                    President and Director of McNeil 
                                      Investors, Inc.
                                    (Principal Financial Officer)




May 18, 1999                    By: /s/  Carol A. Fahs
--------------                     ---------------------------------------------
Date                                Carol A. Fahs
                                    Vice President of McNeil Investors, Inc.
                                    (Principal Accounting Officer)