**Exhibit 12.1**

**CHIEF EXECUTIVEOFFICER CERTIFICATION PURSUANT TOSECTION 302 OF THE SARBANES-OXLEY ACT OF 2002**

I, Narendra K. Patni, certify that:

1.      I havereviewed this annual report on Form 20-F of Patni Computer SystemsLimited, hereinafter referred to as the Company, for the year ended December 31,2006;

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

3.      Based onmy knowledge, the financial statements, and other financial informationincluded in this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the Company as of, and for,the periods presented in this report;

4.      TheCompany’s other certifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13-a-15(f) and 15(d)-15(f) forthe Company and have:

(a)    Designedsuch disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the Company, including its consolidated subsidiaries,is made known to us by others within those entities, particularly during the periodin which this report is being prepared;

(b)   Designedsuch internal control over financial reporting, or caused such internal controlover financial reporting to be designed under our supervision, to providereasonable assurance regarding the reliability of financial reporting and thepreparation of financial statements for external purposes in accordance withgenerally accepted accounting principles;

(c)    Evaluatedthe effectiveness of the Company’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by thisreport based on such evaluation; and

(d)   Disclosedin this report any change in the Company’s internal control over financialreporting that occurred during the period covered by the annual report that hasmaterially affected, or is reasonably likely to materially affect, the Company’sinternal control over financial reporting; and

5.      TheCompany’s other certifying officers and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to the Company’sauditors and the Audit Committee of the Company’s board of directors (orpersons performing the equivalents functions):

(a)    All significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting, which are reasonably likely to adverselyaffect the Company’s ability to record, process, summarize and report financialinformation; and

(b)   Any fraud,whether or not material, that involves management or other employees who have asignificant role in the Company’s internal control over financial reporting.

Date: June 29, 2007

/s/ Narendra K. PatniNarendra K. PatniChief Executive Officer

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