Exhibit
31.1




CERTIFICATION









I,
Michael W. Laphen, certify that:




1.  I have reviewed
this  annual report on Form 10-K of Computer Sciences
Corporation;




2.  Based on my
knowledge, this report does not contain any untrue statement of a material fact
or omit to state a material fact necessary to make the statements made, in
light  of the circumstances under which such statements were made, not
misleading with respect to the period covered by this report;




3.  Based
on my knowledge, the consolidated financial statements, and other financial
information included in this annual report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this report;




4.  The
registrant’s other certifying officer and I are responsible for establishing and
maintaining disclosure controls and procedures (as defined in Exchange Act rules
13a-15(e) and 15d-15(e)) and internal control over financial reporting (as
defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and we
have:




a)  Designed
such disclosure controls and procedures, or caused such disclosure controls and
procedures to be designed under our supervision, to ensure that material
information relating to the registrant, including its consolidated subsidiaries,
is made known to us by others within those entities, particularly during the
period in
which this report is being prepared;




b)  Designed
such internal control over financial reporting, or caused such internal control
over financial reporting to be designed under our supervision, to provide
reasonable assurance regarding the reliability of financial reporting and the
preparation of financial statements for external purposes in accordance with
generally accepted accounting principles;




c)  Evaluated
the effectiveness of the registrant’s disclosure controls and procedures and
presented in this report our conclusions about the effectiveness of the
disclosure controls and procedures, as of the end of the period
covered by this report based on such evaluation; and




d)  Disclosed
in this report any change in the registrant’s internal control over financial
reporting that occurred during the registrant’s fourth fiscal quarter that has
materially affected, or is reasonably likely to materially affect, the
registrant’s internal control over financial reporting; and




5.  The
registrant’s other certifying officer and I have disclosed, based on our most
recent evaluation of internal control over financial reporting, to the
registrant’s auditors and the audit committee of registrant’s board of directors
(or persons performing the equivalent function):




a)  All
significant deficiencies and material weaknesses in the design or operation of
internal control over financial reporting which are reasonably likely to
adversely affect the registrant’s ability to record, process, summarize
and report financial information; and




b)  Any
fraud, whether or not material, that involves management or other employees who
have a significant role in the registrant’s internal controls over financial
reporting.




Date:  May
      28, 2009
            
            
            /s/Michael
      W. Laphen
              Chief
      Executive
Officer