<PAGE>

                               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 26, 1998

[ ]  Transitional report pursuant to section 13 or 15(d) of the Securities
     Exchange Act of 1934 for the transition period from ______ to ______.

Commission File Number 0-13381

                                 MYLEX CORPORATION
                ----------------------------------------------------
               (Exact name of registrant as specified in its charter)


           DELAWARE                                     59-2291597
-------------------------------                ----------------------------
(State or other jurisdiction of                       (IRS Employer
incorporation or organization)                      Identification No.)


   34551 Ardenwood Boulevard
        Fremont, California                               94555
-------------------------------------           --------------------------
(Address of principal executive office)                 (Zip code)

Registrant's telephone number, including area code: 510-796-6100

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

Securities registered pursuant to Section 12(g) of the Exchange Act: Common
Stock, $.01 par value

                                       1

<PAGE>

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 (or for such shorter period that the registrant was
required to file such reports) and (2) has been subject to such filing
requirements for the past 90 days.     Yes   X      No
                                           -----       -----

As of February 12, 1999, registrant had 19,944,393 outstanding shares of 
Common Stock.  The aggregate market value of the voting stock held by 
non-affiliates of the registrant, based upon the mean of the closing sale 
price of the Common Stock on February 12, 1999, as reported by NASDAQ, was 
$89,423,021.  Shares of Common Stock held by each executive officer and 
director and by each person who owns 5% or more of the outstanding Common 
Stock have been excluded in that such persons may be deemed to be affiliates. 
This determination of affiliate status is not necessarily a conclusive 
determination for other purposes.

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 the definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this form 10-K.  [  ]


                        DOCUMENTS INCORPORATED BY REFERENCE

Parts II and IV incorporate information by reference from the Annual Report to
Stockholders for the year ended December 26, 1998.  Part III incorporates
information by reference from the definitive proxy statement for the 1999 Annual
Meeting of Stockholders to be held May 17, 1999, which proxy statement will be
filed in April 1999.

                                       2

<PAGE>

                                  TABLE OF CONTENTS

                                        PART I

<TABLE>
<CAPTION>

                                                                      Page
                                                                      -----
<S>       <C>                                                         <C>
Item  1.  Business                                                      5

Item  2.  Properties                                                   14

Item  3.  Legal Proceedings                                            15

Item  4.  Submission of Matters to a
            Vote of Security Holders                                   15


                                      PART II 

Item  5.  Market for Registrant's Common Equity and
            Related Stockholder Matters                                17

Item  6.  Selected Financial Data                                      17

Item  7.  Management's Discussion and Analysis of
            Financial Condition and Results
            of Operations                                              17

Item  7a. Quantitative and Qualitative Disclosure about
            Market Risk                                                17

Item  8.  Consolidated Financial Statements and
            Supplementary Data                                         17

Item  9.  Changes in and Disagreements with 
            Accountants on Accounting and 
            Financial Disclosure                                       18


                                     PART III 

Item 10.  Directors and Executive Officers
            of the Registrant                                          19

Item 11.  Executive Compensation                                       19

Item 12.  Security Ownership of Certain
            Beneficial Owners and Management                           19

                                      3

<PAGE>

Item 13.  Certain Relationships and Related
            Transactions                                               19


                                    PART IV 

Item 14.  Exhibits, Consolidated Financial Statements,
            Financial Statement Schedules, and
            Reports on Form 8-K                                        20

</TABLE>











                                       4

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                                   PART I 

ITEM 1.    BUSINESS

GENERAL

Mylex Corporation is a leading producer of RAID technology and network 
management products.  Mylex produces high performance disk array (RAID) 
controllers, PCI bus based and external, Ultra SCSI host bus adapters (HBA) 
and complementary computer products for network servers, mass storage systems 
and workstations.  Through its wide range of RAID controllers and HBA 
products, Mylex provides enabling intelligent I/O technologies that increase 
network management control, enhance CPU utilization, optimize I/O 
performance, and ensure data security and availability.  Products are sold 
globally through a network of OEMs, major distributors, VARs and system 
integrators.  Through 1998, more than twenty leading network file server and 
storage subsystem OEMs, including Digital/Compaq, Siemens, NEC, Fujitsu, and 
MTI had designed Mylex RAID controllers into their server and storage 
subsystem products.  The Company is incorporated under the laws of the State 
of Delaware.  

In the early 1990s, Mylex responded to changes in the computer industry by 
undertaking a series of product development initiatives designed to address 
the storage and input/output, or "I/O," challenges facing the emerging 
client/server computing environment.  In 1992, the Company introduced its 
first RAID controller product into the personal computer network market.  
Sales of RAID controller products have grown rapidly since 1992, and 
represented 95% of the Company's net sales during 1998. 

The trend toward client/server computing that began in the mid-1980s has 
placed particular demands on network storage systems and related I/O 
functions. The development of faster microprocessors and more robust computer 
bus architectures in network systems has often outstripped the capabilities 
of data storage and I/O technologies, leading to systems "bottlenecks." To 
alleviate or avoid such bottlenecks, networks require continual improvements 
in stored data retrieval speed. In addition, the development of more complex 
applications and operating systems has created the need for increased network 
storage capacity. Meanwhile, the mission critical, enterprise-wide nature of 
networked computing often requires a high level of "fault tolerance," or the 
ability to preserve data from loss and to provide uninterrupted system 
service even if an individual data storage device fails. The emergence of 
data-intensive applications such as the Internet, E-commerce, multimedia and 
video-on-demand are further driving the demands for speed, capacity and 
reliability in network storage devices. 

Mylex RAID controllers enable increased speed, greater capacity, and a high 
degree of fault tolerance in network storage and I/O functions. RAID, which 
stands for redundant array of independent disks, is a method for distributing 
data across several disk drives and allowing the server microprocessor to 
access those drives simultaneously, thus 

                                       5

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increasing system storage I/O performance.  In addition, lost data on any 
drive can be recreated using special RAID algorithms, thus ensuring the 
immediate availability of RAID protected data even in the event of a disk 
drive failure.  Mylex controllers support all major operating systems and 
both PCI and independent bus types, and the Company endeavors to rapidly 
develop products for new bus technologies, operating systems, and platform 
standards as they are defined.  The Company believes that its patents, 
proprietary software and firmware, as well as its large installed base of 
RAID units, are key competitive advantages in the RAID controller market. 

In addition to the PCI RAID controllers, which generated approximately 80% of 
the Company's revenues in 1998, the Company offers external RAID controllers, 
including several fibre versions and host bus adapters (HBA).  Both the 
external RAID controllers and HBA products are highly suited to applications 
that demand high data throughput and low CPU utilization.  Consequently, the 
Company has an offering of product solutions for desktop PC's to large 
networked systems.    

FACTORS THAT MAY AFFECT FUTURE OPERATING RESULTS

Sales of the Company's RAID controller products accounted for 95% of the 
Company's net sales in 1998 and 88% of net sales in 1997. Conversely, the 
Company's net sales of its host bus adapters (HBA's) were 3% in 1998 and 10% 
in 1997.  The Company's RAID controller products are used principally in 
personal computer network applications and Unix-based work stations.  The use 
of RAID technology in the personal computer network market has become 
established over the last few years, but there can be no assurance that 
another technology will not replace RAID in the disk array controller 
marketplace or that there will be continuing widespread acceptance or growth 
of the use of RAID products in general, or the Company's RAID controllers in 
particular, in that market. Furthermore, even if the market continues to 
grow, there can be no assurance that the Company will be able to continue to 
market and sell its RAID controller products at similar or higher volumes, or 
with similar gross margins.  The Company expects gross margins to be lower 
than 1998 due to intense competition in the market place and the added 
expense of the license agreement with EMC Corporation signed in December 
1998. 

In addition, in order to be able to compete successfully in the RAID 
controller market, the Company will have to develop and market new RAID 
controllers. There can be no assurance that the Company will be able to 
develop and introduce new RAID controller products in a timely manner or that 
any such products will gain or sustain market acceptance. 

The Company's 1998 revenue depended on a customer base that was concentrated. 
The Company's four largest customers, Digital/Compaq, Siemens, NEC and 
Fujitsu collectively accounted for 54% of the Company's net sales in 1998.  
Sales to Digital/Compaq alone represented 25% of the Company's net sales 
during 1998. Sales to Siemens, NEC and Fujitsu accounted for 16%, 8% and 5% 
of net sales, respectively.  The Company has no long-term purchase 
commitments from its customers, and 

                                      6

<PAGE>

customers generally may cancel their orders on 30-days notice. Due to 
Compaq's acquisition of DEC in February 1998, there has been product 
consolidation between the two companies that has had and may continue to have 
an impact on the Company's revenues.  Although the full impact of these 
product line consolidations is not known at this time, the Company estimates 
that its net sales to Digital/Compaq in 1999 will be approximately 30% to 40% 
less than 1998 net sales to that customer.  Furthermore, there can be no 
assurance that orders from other existing customers, including the Company's 
other principal customers, will continue at their historical levels, or that 
the Company will be able to obtain orders from new customers. The loss of one 
or more of the Company's current customers, particularly a significant 
customer, or cancellation or rescheduling of orders already placed, could 
materially and adversely affect the Company's business and operating results. 

The Company's OEM customers have integrated the Company's RAID controller 
products into their servers and storage subsystems. Any of these OEM 
customers may choose to develop their own RAID controller products that could 
be substituted for, and thus reduce or eliminate their purchases of the 
Company's RAID controller products.  Most of the Company's OEM customers, and 
particularly its principal customers, have extensive product development 
experience and expertise, substantial financial resources and ongoing, 
substantial product development activities. As a result, it is possible that 
those customers may engage in RAID development programs on a continuing 
basis.  Any material reduction in purchases of RAID controller products by 
any OEM customer as a result of such customer developing its own competing 
product will materially and adversely affect the Company's business and 
operating results. 

COMPETITION

The markets for the Company's RAID controller and HBA products have been 
competitive and are likely to remain competitive.  Furthermore, there are 
numerous companies with established reputations in the controller and 
personal computer related markets, many of which have greater financial, 
manufacturing and marketing resources than those of the Company.  The Company 
believes that its principal competitors for RAID controllers are American 
Megatrends, DPT, Infotrend, ICP Vortex and Adaptec, which also has been the 
Company's principal HBA competitor.  The Company's share of the HBA market is 
relatively small, particularly when compared to Adaptec's share, and Adaptec 
has significantly greater financial, manufacturing and marketing resources 
than the Company.  In response to the competition that Adaptec has offered 
against the Company's HBA products, the Company introduced in the latter half 
of 1998 a low cost RAID solution to both its OEM customers and distribution 
channels.  As the price point for RAID becomes low enough to supplant 
high-end HBA products, the overall market place demand for HBA products, 
including the Company's products, will continue to decline. 

                                       7

<PAGE>

Some OEMs, such as Compaq and IBM, have developed their own RAID controllers. 
As noted, those customers historically accounting for the most significant 
volumes of the Company's sales are major OEMs, any of which could develop 
their own controllers at any time rather than purchase such products from the 
Company. 

The Company's ability to compete successfully in the RAID controller markets 
depends upon its ability to continue to develop products, which are proven to 
be reliable and obtain market acceptance, and which can be sold at 
competitive prices, while maintaining adequate gross margin levels.  Although 
the Company believes that its RAID controller products have certain 
competitive advantages, which include performance and cost, there can be no 
assurance that the Company will be able to compete successfully in the future 
in the market for such products or that other companies may not develop 
products with greater performance or more favorable prices and thus reduce 
the demand for the Company's products.  Furthermore, as more companies enter 
the RAID controller market, the Company expects to encounter price 
competition for such products which could materially and adversely affect its 
gross margins.  Additionally the Company is dependent upon the success of its 
major OEM's products which incorporate the Company's RAID controllers.  

PRODUCTS

During the last half of 1993, the Company shifted its principal activity from 
the supply of system board products to the manufacture of I/O devices and 
storage management enhancing computer peripheral products.  Mylex designs its 
products to provide solutions for all popular operating systems, including 
Novell Netware, Windows NT, SCO UNIX, Solaris and Unixware.  Mylex products 
also work with all popular hardware platforms.  These include personal 
computer platforms that use PCI architecture and workstation platforms, 
including Sun Microsystems, Silicon Graphics and IBM RS-6000 workstations 
that use the Company's SCSI or Fibre based products. 

Despite testing, new products may be affected by quality, reliability or 
interoperability problems, which could result in returns, delays in 
collecting accounts receivable, unexpected service or warranty expenses, 
reduced and delayed orders and a decline in the Company's competitive 
position.  In addition, there can be no assurance that new products or 
technologies developed by others, or the emergence of new industry standards, 
will not render the Company's products or technologies noncompetitive or 
obsolete.  For example, efforts by the Company's OEM customers and other 
manufacturers to integrate additional functions into system boards, to use 
chip sets that incorporate additional functionality, or to design and utilize 
their own controllers and other devices rather than purchase the Company's 
products could have a material adverse effect on the Company's business and 
operating results. 

All of the Company's current RAID controller products are based on the Intel 
i960 or StrongARM-Registered Trademark- family of processors.  If another 
company develops a processor for RAID applications which renders the Intel's 
embedded processors noncompetitive, whether as 

                                       8

<PAGE>

a result of cost, specifications or other advantages of the new processor, or 
if Intel ceases to produce either the i960 or StrongARM-Registered Trademark- 
processors or support the Company's efforts to develop products based on the 
i960 or StrongARM-Registered Trademark-processors, the Company will be forced 
to develop new products based on another processor. Such development efforts 
will be costly, and there can be no assurance that the Company will be able 
to timely complete such development efforts or that such products, if 
developed, will have the same degree of market acceptance or the same gross 
margin as the Company's present RAID products. 

Raid Controllers

Most of the Company's bus-based RAID controller includes a proprietary 
application specific integrated circuit, or "ASIC," that serves as an 
interface with the host computer, a RISC processor, up to three SCSI channels 
to manage the transfer of data to and from the disk drives in the array and a 
dynamic cache memory ranging in size from 4 to 128 MB, depending on the 
product, to buffer the transfer of information to and from the disks.  The 
controller also includes Mylex firmware residing on an EEPROM that implements 
the RAID algorithms and the algorithms necessary for the cache and supporting 
software, including I/O drivers, configuration utilities and system 
monitoring programs. 

Mylex disk array controllers DAC960PG, DAC960PJ, eXtremeRAID and AcceleRAID 
provide high performance, fault tolerant data storage solutions for the PCI 
bus platforms.  The Mylex external disk array controllers, DAC960SF, 
DAC960FL, DACFF and DAC960SX, bring the performance of RAID technology, which 
can operate in dual active mode, to virtually any hardware platform without 
requiring special host software.  The Mylex disk array products are designed 
for both internal and external storage options and are compatible with most 
commonly used operating systems. 

Products currently under development include a controller optimized for the 
Internet, multimedia and video imaging, PCI-to-Fibre based controller and 
low-cost RAID solutions.  There can be no assurance that the Company will 
introduce its products under development. If these products are introduced, 
there can be no assurance that they will gain or sustain market acceptance or 
that their sales will produce adequate gross margins. 

The markets for the Company's products are characterized by rapidly changing 
technology, evolving industry standards and relatively short product life 
cycles. The Company's ability to compete successfully will depend on its 
ability, on a timely and cost-effective basis, to enhance its existing 
products and to introduce new products, such as its new PCI and external disk 
array controllers, with features that meet changing customer requirements and 
with competitive prices.  There can be no assurance that the Company will be 
successful in doing so.  Delays in product enhancement and development or the 
failure of the Company's new products or enhancements to gain or sustain 
market acceptance could have a material adverse effect on the Company's 
business and operating results. 

                                      9

<PAGE>

PRODUCT MANUFACTURE AND SUPPLIERS

Manufacturing of the Company's products entails placing semiconductors and 
other electronic components on printed circuit boards and soldering them in 
place through an automated process.  The Company signed a manufacturing 
agreement in February 1999 with Dovatron International, Inc. (Dovatron), a 
wholly-owned subsidiary of the DII Group of Colorado, which is an ISO 9000 
certified manufacturer that specializes in turnkey manufacturing.  Dovatron 
will be providing all of the Company's manufacturing needs pursuant to the 
terms and conditions of the agreement.  The Company anticipates that the 
agreement will be fully implemented in the second quarter of 1999.  In this 
arrangement, Dovatron will become the Company's sole turnkey manufacturer, 
procuring the Company's raw materials and assembling, testing, configuring 
and shipping all of its products. The anticipated benefits from this 
relationship are a focused supplier that should consistently deliver high 
quality products on a timely basis, that will leverage its purchasing power 
for the benefit of the Company and that will be able to better deliver 
state-of-the-art assembly and testing capabilities. Despite its arrangements 
with Dovatron, however, there can be no assurance that the Company's 
manufacturing resources will always be adequate to meet product demand.  
Furthermore, as Dovatron will be the sole provider of purchasing and 
manufacturing for the Company, it will have reduced ability to bring other 
purchasing and manufacturing services providers on stream in the event that 
Dovatron were unable to perform those functions on a timely basis.

As part of the Company's arrangement with Dovatron, the Company has agreed to 
sublease to Dovatron approximately 32,000 square feet of manufacturing and 
related space in one of its Fremont buildings.  In addition Dovatron has 
hired 33 employees of the Company included in its manufacturing operations.  
These employees were involved in activities that Dovatron has contracted to 
perform for the Company.

Mylex, through its turnkey manufacturing arrangement, performs quality 
control and inspection procedures throughout the production process to ensure 
that products meet industry standards. The Company's turnkey manufacturer 
subjects all products to 100% in-circuit and functional tests.

The Company's most critical components are the Intel i960 and 
StrongARM-Registered Trademark- RISC processors, the Company's applications 
specific integrated circuits or "ASIC", SCSI chips and the SIMM memory 
module. The Company or its turnkey manufacturer procures the Intel processors 
through local distributors and its ASIC, SCSI chips and SIMM modules from 
Toshiba, LSI Logic, Atmel and Southland Corporation, respectively.  Other 
components are available from several sources at competitive prices. 

The Company has no long-term supply contracts.  There can be no assurance 
that the Company will be able to obtain, on a timely basis, all the 
components it requires.  In the event a sole source supplier is unable or 
unwilling to provide a component, there could be substantial delays in the 
Company obtaining a new supplier for such components and the 

                                      10

<PAGE>

replacement supplier may charge materially more for such components.   If the 
Company cannot obtain components, and particularly critical components, as 
required, it may be unable to meet demand for its products, thereby adversely 
affecting its operating results.  In addition, scarcity of such components 
may also result in cost increases and adversely affect the Company's gross 
margins. 

The Company's need to manufacture products before receiving firm purchase 
orders, combined with risks of technological obsolescence and rapid shifts in 
market demand, could result in inventory devaluation or obsolescence, either 
of which could have a material adverse effect on its operating results. 

SALES AND MARKETING
     
As of December 26, 1998, the Company employed 90 sales and sales support 
personnel who devoted substantially all their time to marketing, sales, and 
technical and customer support.  The Company expects that sales and marketing 
expenses will increase in 1999, particularly if the rate of sales grows. 
However, there can be no assurance that such sales growth will occur.

Sales to Digital/Compaq accounted for 25% of net sales in 1998 and 23% of net 
sales in 1997.  Sales to the next two largest customers, Siemens and NEC, 
each accounted for an additional 16% and 8% of net sales, respectively, in 
1998 and 10% and 8%, respectively, in 1997.  The majority of the Company's 
sales are with OEM customers, and sales continue to remain concentrated in a 
small group of OEM customers.  In addition in 1998, the export portion of the 
Company sales has remained at 75%, the percentage in 1997.  Although there 
are OEM agreements in place with some of the Company's largest customers that 
define the terms of sale and support services, these agreements do not 
include specific quantity commitments and generally allow customers to cancel 
any orders on 30 days notice.  The Company generally sells products on a 
purchase order basis.  As a result, historical sales are not necessarily an 
accurate indicator of future sales. 

The OEM sales process is complex, requiring interaction with several layers 
of the OEM customer's organization and extensive technical exchanges, product 
demonstrations and commercial negotiations.  As a result, the Company's 
typical sales cycle is usually four to nine months.  OEM relationship 
commitments are generally made at a high level within the customer's 
organization, and the sales process involves broad participation across the 
Mylex organization, from the Chief Executive Officer to the engineers who 
designed the product. 

The Company's sales to other than OEM's involve the marketing and 
distribution of the Company's products to system integrators, value added 
resellers and distributors (who also service major OEM customers in some 
international markets) throughout the world. Mylex also uses the services of 
manufacturer representatives in the United States in this sales channel. 

                                       11

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The Company has distribution agreements with its distributors, including 
companies such as Tech Data and Ingram Micro.  Mylex also has agreements with 
various regional and specialty distributors, both domestic and international. 
The Company also conducts extensive advertising in trade publications, 
conducts various joint marketing activities with its distributors, and 
sponsors exhibits at approximately 10 trade shows annually. 

INTERNATIONAL SALES

Sales to customers outside the United States accounted for approximately 75% 
of the Company's revenue in 1998.  Sales to foreign affiliates of U.S. 
customers are treated as foreign sales.  Of the total international sales, 
21% of these sales were destined to Pacific Rim customers.  Although there 
can be no assurances given, the Company expects that international sales will 
continue to represent a significant portion of the Company's revenue in 1999 
and thereafter. 

International sales pose certain risks not faced by companies that limit 
themselves to domestic sales.  Fluctuations in the value of foreign 
currencies relative to the U.S. dollar, as occurred in 1998, for example, 
could make the Company's products less price competitive and, if the Company 
in the future denominates any of its sales in foreign currencies, could 
result in losses from foreign currency transactions.  International sales 
also could be adversely affected by factors beyond the Company's control, 
including the imposition of government controls, export license requirements, 
restrictions on technology exports, changes in tariffs and taxes and general 
economic and political conditions. In some countries, the laws do not protect 
the Company's intellectual property rights to the same extent as the laws in 
the United States. 

BACKLOG 

The Company's backlog as of December 26, 1998, totaled $15.2 million, as 
compared to $5.4 million as of December 27, 1997.  The increase in the 
backlog was attributable to the market acceptance of the Company's external 
RAID product and the strong demand for this product line demonstrated in the 
fourth quarter of 1998.  Because almost all of the orders for the Company's 
products may be canceled prior to shipment and customers may similarly change 
delivery schedules, the Company believes that backlog as of any particular 
date may not be indicative of actual net revenues for any succeeding period.  
Furthermore, the Company's manufacturing capabilities may not be sufficient, 
from time to time, to permit it to ship all products subject to a substantial 
backlog by the shipment dates requested by the respective customer.  Of the 
total $15.2 million backlog at December 26, 1998, all but a small percentage 
of the orders would have delivered within the three months ended March 27, 
1998, unless the orders were canceled or rescheduled by the respective 
customer.

YEAR 2000

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For a discussion of the impact on the Company of various matters with respect 
to Year 2000 compliance issues, please refer to Management's Discussion and 
Analysis of Financial Condition and Results of Operations in the Company's 
Annual Report on Form 10-K for its year ended December 26, 1998.

RESEARCH AND DEVELOPMENT

The Company conducts an active and ongoing research and development 
engineering program that focuses on the development of new products, new 
features for the Company's existing products, and rigorous design 
verification and compatibility testing. The Company also maintains an 
engineering support group to provide follow up with its customers.  The 
Company has continued to expand its development activities, and now has two 
engineering groups, one located in Fremont, California and the other in 
Boulder, Colorado. 

As part of its product development strategy, the Company actively seeks 
cooperative and codevelopment activities with industry leaders in the 
hardware, software, silicon and systems businesses and participates in a 
number of industry forums, such as NGIO Forum, Fibre Channel Loop Community 
and PCI RAID Advisory Group.  The Company's ability to compete successfully 
will depend in large part on its ability, on a timely and cost-effective 
basis, to timely enhance its existing products and introduce new products 
with features that meet changing customer requirements and with competitive 
prices. Despite testing, new products may be affected by quality, reliability 
and interoperability problems, which could result in returns, delays in 
collecting accounts receivable, unexpected service or warranty expenses, 
reduced orders and a decline in the Company's competitive position. 

EMPLOYEES

As of December 26, 1998, the Company employed 345 people.  Those employees 
included 134 engineering and product development employees, 48 finance and 
administration employees, 90 employees in the sales, marketing and technical 
and customer support areas, and 73 manufacturing employees. 

Recruitment of personnel in the computer industry, particularly engineers, is 
highly competitive. The Company believes that its future success will depend 
in part on its ability to attract and retain highly skilled management, 
engineers, sales, marketing, finance and technical personnel.  There can be 
no assurance of the Company's ability to recruit and retain the employees 
that it may require. 

                                       13

<PAGE>

INTELLECTUAL PROPERTY

The Company holds four patents with respect to its RAID controller products.  
It also has several other patent applications, applicable to its RAID 
controller products, in different phases of review.  Otherwise the Company 
relies on a combination of trade secret, copyright and trademark laws and 
employee and third party non-disclosure agreements to protect its 
intellectual property. There can be no assurance that the steps taken by the 
Company to protect its rights will be adequate to prevent misappropriation of 
the Company's technology or to preclude competitors from developing products 
with features similar to the Company's products. 

Certain patents and copyrights owned by others are of critical importance to 
the industry segments in which the Company operates.  The Company has 
obtained such licenses to certain technology protected by patents and 
copyrights as the Company believes are necessary for the operation of its 
business as presently conducted.  In December 1998, the Company signed a 
cross license agreement with EMC, requiring an up-front payment against 
future royalties.  This cross license agreement covers all of the Company's 
RAID products sold to its customers that do not currently have RAID license 
agreements with EMC.  The agreement provides for a certain rate for 
approximately one year after which, the Company will be obligated to pay 
royalties, at a relatively lower rate, for as long as the Company's products 
are covered by the EMC patents.  The Company expects that its payments to EMC 
will have an adverse impact on its gross margins in the foreseeable future.  
The Company may be required to obtain licenses from others, and there are no 
assurances that such licenses would be available on terms satisfactory to the 
Company or at all. 

There can be no assurance that third parties will not assert intellectual 
property infringement or related indemnity claims against the Company.  In 
that circumstance, asserting the Company's rights or defending against third 
party claims could involve substantial expense, which could materially and 
adversely affect the Company's results of operations. 

ITEM 2.  PROPERTIES

The Company's headquarters, manufacturing and distribution facilities are 
located in two buildings, with a combined square footage of 133,182, in 
Fremont, California.  The Company also has an engineering facility with 
approximately 25,000 square feet in Boulder, Colorado, whose lease expires in 
December, 2000. Approximately 74,000 square feet of the Fremont facilities is 
leased through April, 2001, while the remaining square footage will be on 
lease through July, 2003. 

                                       14

<PAGE>

ITEM 3.  LEGAL PROCEEDINGS

In January 1999, the Company settled an action brought against the Company 
and its outside directors in 1994 by a former Chief Executive Officer.  In 
the settlement, the Company agreed to pay $2 million in cash and issue 
warrants to purchase 400,000 shares of its Common Stock (estimated fair value 
of $2.2 million).  In return for a complete release of all claims the 
plaintiff might have against the defendants.

In July 1998, a complaint against the Company, for breach of contract and 
open book account, was filed in the Superior Court of the State of California 
for the County of Santa Clara by Pioneer-Standard of Maryland, Inc.  Pioneer 
alleges the breach of a purchase agreement for failure of the Company to 
repurchase excess inventory at the conclusion of the contract.  Pioneer's 
complaint sought damages in the sum of approximately $1,150,000 plus 
interest.  Recent submissions by Pioneer, however, suggest that it has 
reduced its damages claim to approximately $964,000 plus interest.  In August 
1998, the Court denied Pioneer's motion for a writ of attachment.  The 
Company has filed an answer denying Pioneer's claims and has filed a 
cross-complaint alleging overcharging by Pioneer.  The case currently is in 
the discovery phase.

In addition to matters discussed above, the Company is a party to routine 
suits and claims arising in the ordinary course of its business which the 
Company does not believe will have a material adverse effect on its business. 

ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
                                          
Not applicable

SAFE-HARBOR" STATEMENT UNDER PRIVATE SECURITIES LITIGATION REFORM ACT OF 
1995: The foregoing discussion in this annual report on Form 10-K contains 
forward-looking information with respect to plans, projections or future 
performance of the Company, the occurrence of which involve certain risks and 
uncertainties that could cause actual results to differ materially. These 
risks and uncertainties include, without limitation, changes in customer 
order patterns, particularly those resulting from fluctuations in actual or 
projected server shipments; demand and competition for the Company's existing 
and new products, particularly its RAID controller and SCSI host adapter 
products; component availability; pricing pressures; the ability of the 
Company to ship ordered product in a timely manner; business conditions and 
growth in the computer industry and general economy; instability in foreign 
economies, particularly in Asia; the capability of the Company to meet the 
rapidly changing needs of its markets through timely product enhancements or 
new product introductions; the risk of inventory obsolescence due to shifts 
in market demand or other causes; the risk of a Company product being 
incompatible with new products of other companies; unanticipated costs and 
risks of litigation; the Company's ability to generate sufficient future 
taxable income 

                                       15

<PAGE>

to utilize its recognized deferred tax assets; the risk that any of its 
systems or products, or vendors, suppliers or customers may not be Year 2000 
compliant, and other risks and uncertainties detailed in the Company's 
filings with the Securities and Exchange Commission, including this Form 10-K 
and Form 10-Q filings for the period ended March 28, 1998, June 27, 1998 and 
September 26, 1998.  These forward-looking statements speak only as of the 
date hereof, and the Company disclaims any intent or obligation to update 
such statements.







                                       16

<PAGE>

                                    PART II

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

This information is incorporated by reference from the information under the 
caption "Market for Registrant's Common Equity and Related Stockholder 
Matters" on page 7 of the Consolidated Financial Statements contained within 
the Annual Report to Stockholders for the year ended December 26, 1998.

ITEM 6.  SELECTED FINANCIAL DATA

This information is incorporated by reference from the information under the 
caption "Selected Five Year Consolidated Financial Data" on page IFC of the 
Consolidated Financial Statements contained within the Annual Report to 
Stockholders for the year ended December 26, 1998.

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

All other information regarding management's discussion and analysis of 
financial condition and results of operations are incorporated by reference 
from the information under the caption "Management's Discussion and Analysis 
of Financial Condition and Results of Operations" on pages 1 through 6 of the 
Consolidated Financial Statements contained within the Annual Report to 
Stockholders for the year ended December 26, 1998.

ITEM 7a. QUANTITATIVE AND QUALITATITVE DISCLOSURE ABOUT MARKET RISK

At December 26, 1998 the Company had a non-trading investment portfolio of 
fixed income securities, excluding those classified as cash and cash 
equivalents of $34.7 million (see note 4 of the Company's Consolidated 
Financial Statements). These securities, like all fixed income instruments, 
are subject to interest rate risk and will fall in value if market interest 
rates increase.  If market interest rates were to increase immediately and 
uniformly by 100 basis points from level as of December 26, 1998, the fair 
market value of the portfolio would decline by approximately $124,000.

ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Consolidated financial statements of Mylex Corporation at December 26, 1998 
and December 27, 1997 and for each of the years in the three-year period 
ended December 

                                        17

<PAGE>

26, 1998 and the Independent Auditor's Report thereon are incorporated by 
reference from pages 8 through 21 of the Consolidated Financial Statements 
contained within the Annual Report to Stockholders for the year ended 
December 26, 1998.

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

Not applicable.







                                        18

<PAGE>

                                      PART III
                                          
Item 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

This information is incorporated by reference from the information under the 
caption "Election of Directors" and "Executive Officer Compensation" in the 
Registrant's definitive Proxy Statement for its 1999 Annual Meeting of 
Stockholders.

ITEM 11. EXECUTIVE COMPENSATION 

This information is incorporated by reference from the information under the 
caption "Executive Officer Compensation" in the Registrant's definitive Proxy 
Statement for its 1999 Annual Meeting of Stockholders.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

This information is incorporated by reference from the information under the 
caption "Securities Ownership of Management and Principal Stockholders" in 
the Registrant's definitive Proxy Statement for its 1999 Annual Meeting of 
Stockholders.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

This information is incorporated by reference from the information under the 
caption "Certain Relationships and Related Transactions" in the Registrant's 
definitive Proxy Statement for its 1999 Annual Meeting of Stockholders.




                                       19

<PAGE>

                                  PART IV

Item 14.  Exhibits, Financial Statement Schedules and Reports on Form 8-K.

The following Consolidated Financial Statements of Mylex Corporation and the 
Independent Auditor's Report, as listed under (a) (1) below, are incorporated 
herein by reference from the Registrant's Annual Report to Stockholders for 
the year ended December 26, 1998.

(a) (1)   Financial Statements

<TABLE>
<CAPTION>

                                                                         Page in
                                                                  Consolidated Financial
                                                                 Statements contained in
                                                                    the Annual Report
                                                                 ----------------------
<S>                                                             <C>
Consolidated Statements of Operations - Years ended December,
1998, 1997 and 1996                                                         9
 
Consolidated Balance Sheets at December, 1998 and 1997                      8

Consolidated Statements of Cash Flows - Years ended December,              11
1998, 1997 and 1996  

Consolidated Statements of Shareholder' Equity - Years ended               10
December, 1998, 1997 and 1996 

Notes to Consolidated Financial Statements                              12-20

Independent Auditor's Report                                               21

</TABLE>

(2)  The following financial statement schedule and report are submitted
     herewith:

<TABLE>
<CAPTION>

                                                                         Page in
                                                                       this Report
                                                                       -----------
<S>                                                                   <C>

Schedule I - Independent Auditors' Report                                   25

Schedule II - Valuation and Qualifying Accounts                             26

</TABLE>

                                       20

<PAGE>

(3)  Exhibits included herein:

<TABLE>
<CAPTION>

Exhibit No.    Exhibit
<S>           <C>

     3.1       (h) Certificate of Incorporation, Articles of Merger and
                   Agreement and Plan of Merger.

     3.1.1     (a) Certificate of Amendment of Certificate of Incorporation.

     3.2       (i) By-laws.

     10.10     (c) 1983 Incentive Stock Option Plan, as amended and restated.

     10.11     (k) 1993 Stock Option Plan, as amended.

     10.13     (i) 1995 Employee Stock Purchase Plan, as amended and restated.

     10.14     (a) 1998 Employee Stock Purchase Plan.

     10.20     (b) Lease Agreement of premises at 34551 Ardenwood Boulevard,
                   dated March 6, 1991.

     10.20.1   (g) Amendment to Lease Agreement of premises at 34551 Ardenwood
                   Boulevard, dated February 26, 1996.

     10.21     (f) Security and Loan Agreement, dated June 28,1996, with
                   Comerica Bank

     10.21.1   (l) Second Amendment to Revolving Credit Loan Agreement, dated
                   April 29, 1998, with Comerica Bank.

     10.22     (g) Lease Agreement of premises at 6607 Kaiser Drive, dated
                   December 9, 1995.

     10.23     (a) Sublease Agreement between Mylex Corporation (sublandlord)
                   and Dovatron International, Inc. (subtenant) of portion of
                   premises at 34551 Ardenwood Boulevard, dated February 1,
                   1999.

     10.25     (d) Digital Equipment Corporation Basic Order Agreement.

     10.40     (e) 401(k) Plan; Target Investment Advisory Agreement and
                   Standardized Adoption Agreement.

                                       21

<PAGE>

     10.41     (a) Employment Agreement, dated as of January 1, 1999, with Al
                   Montross.

     10.42     (i) Form of Severance Agreement with Executive Officers.

     10.43     (j) Stockholder Rights Plan, as amended and restated.

     10.44     (a) Manufacturing Agreement with Dovatron International, Inc.,
                   dated as of January 29, 1999.

     10.45     (a) License Agreement with EMC Corporation, dated as of December
                   24, 1998.

     13.1      (a) Selected Five Year Consolidated Financial Data, MD&A, Market
                   for Registrant's Common Equity and Related Stockholder
                   Matters, Consolidated Financial Statements, Notes to
                   Consolidated Financial Statements and the Independent
                   Auditors' Report sections from the Annual Report to
                   Stockholders for the fiscal year ended December 26, 1998.

     23.1      (a) Consent of Independent Auditor, KPMG LLP. 

     27.0      (a) Financial Data Schedule

</TABLE>

(b)  Reports on Form 8-K, none.

---------------------

(a)  Filed herewith

(b)  Filed as an exhibit to the Registrant's Annual Report on Form 10-K, for the
     year ended December 31, 1992, Commission File No. 0-13381, and incorporated
     herein by reference.

(c)  Filed as an exhibit to the Registration Statement on Form S-8, July 24,
     1989, No. 33-30104, and incorporated herein by reference.

(d)  Filed as an exhibit to the Registrant's Quarterly Report on Form 10-Q, for
     the period ended September 30, 1993, and incorporated herein by reference.

(e)  Filed as an exhibit to the Registrant's Annual Report on Form 10-K, for the
     year ended December 31, 1994, and incorporated herein by reference.

                                      22

<PAGE>

(f)  Filed as an exhibit to Registrant's Quarterly Report on Form 10-Q, for
     period ended June 30, 1996, and incorporated herein by reference.

(g)  Filed as an exhibit to Registrant's Annual Report on Form 10-K, for period
     ended December 31, 1995, and incorporated herein by reference.

(h)  Filed as an exhibit to Registrant's Annual Report on Form 10-K, for period
     ended December 31, 1996, and incorporated herein by reference.

(i)  Filed as an exhibit to Registrant's Annual Report on Form 10-K, for period
     ended December 27, 1997, and incorporated herein by reference.

(j   Filed as an exhibit to Registrant's Registration Statement on Form 8-A/A,
     No. 34-13381, on March 22, 1999, and incorporated herein by reference.

(k)  Filed as an exhibit to the Registration Statement on Form S-8, February 3,
     1998, No. 33-30104, and incorporated herein by reference.

(l)  Filed as an exhibit to Registrant's Quarterly Report on Form 10-Q, for
     period ended March 28, 1998, and incorporated herein by reference.


                                       23

<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.

                                        MYLEX CORPORATION


Date: March 25, 1999                    By: /s/ Al Montross
                                           --------------------------------
                                        Al Montross
                                        President and Chief Executive
                                        Officer

Pursuant to the requirements of the Securities Exchange Act of 1934, this Report
has been signed below on March 25, 1999, by the following persons in the
capacities indicated.

<TABLE>
<CAPTION>

       Signature                               Title
       ---------                               -----
<S>                                    <C>

/s/ Ismael Dudhia                       Chairman of the Board of Directors
-----------------------------
Mr. Ismael Dudhia


/s/ M. Yaqub Mirza                      Director
-------------------------
Dr. M. Yaqub Mirza                      


/s/ Inder Singh                         Director
----------------------------
Dr. Inder Singh


/s/ Stephen McKenzie                    Director
-----------------------------
Mr. Stephen McKenzie


/s/ Walt Wilson                         Director
-----------------------------
Mr. Walt Wilson


/s/ Al Montross                         President and Chief Executive Officer 
-----------------------------           and Director
Mr. Al Montross                         (Principal Executive Officer)


/s/ Colleen Gray                        Vice President Finance and Chief
------------------------------          Financial Officer and Secretary
Ms. Colleen Gray                        (Principal Accounting Officer)

</TABLE>

                                       24

<PAGE>

                        MYLEX CORPORATION AND SUBSIDIARIES
                                   SCHEDULE I

                           INDEPENDENT AUDITORS' REPORT


The Board of Directors and Shareholders
Mylex Corporation:

Under date of January 26, 1999, we reported on the consolidated balance 
sheets of Mylex Corporation and subsidiaries (the Company) as of December 26, 
1998 and December 27, 1997, and the related consolidated statements of 
operations, shareholders' equity and cash flows for each of the years in the 
three-year period ended December 26, 1998, as contained in the 1998 Annual 
Report to Shareholders.  These consolidated financial statements and our 
report thereon are incorporated by reference in the December 26, 1998 annual 
report on Form 10-K of Mylex Corporation.  In connection with our audits of 
the aforementioned consolidated financial statements, we also audited the 
related consolidated financial statement schedule.  The financial statement 
schedule is the responsibility of the Company's management.  Our 
responsibility is to express an opinion on this financial statement schedule 
based on our audits.

In our opinion, the financial statement schedule, when considered in relation 
to the basic consolidated financial statements taken as a whole, presents 
fairly, in all material respects, the information set forth therein.

/s/ KPMG LLP

Mountain View, California
January 26, 1999


                                       25

<PAGE>

                        MYLEX CORPORATION AND SUBSIDIARIES
                                   SCHEDULE II

                         VALUATION AND QUALIFYING ACCOUNTS

     YEARS ENDED DECEMBER 26, 1998, DECEMBER 27, 1997 and DECEMBER 31, 1996


<TABLE>
<CAPTION>
                                                                       CHARGED
                                                      BALANCE AT     (BENEFIT) TO     CHARGED                         BALANCE
                                                      BEGINNING        COST AND       TO OTHER                           AT
                   CLASSIFICATION                      OF YEAR         EXPENSES       ACCOUNTS        CHARGES(a)      YEAR-END
                   --------------                      -------         --------       --------        ----------      --------
<S>                                                  <C>            <C>              <C>             <C>             <C>
Amounts deducted from assets to which they apply:

Year ended December 26, 1998
   Allowance for doubtful
      accounts - accounts receivable                 $ 190,000            -               -            (31,000)        159,000

Year ended December 27, 1997
   Allowance for doubtful
      accounts - accounts receivable                 $ 436,000        (227,000)           -            (19,000)        190,000

Year ended December 31, 1996
   Allowance for doubtful
      accounts - accounts receivable                 $ 707,000        (156,000)           -           (115,000)        436,000

</TABLE>


(a)  Doubtful accounts written off, less recoveries.




                                       26