**Exhibit 31.1**

** **

CERTIFICATION OFTHE CHIEF EXECUTIVE OFFICER PURSUANT TO

RULES 13a-14(a) AND15d-14(a) UNDER THE SECURITIES EXCHANGE ACT, AS AMENDED

 

I, Jerre L. Stead, Chairman and Chief ExecutiveOfficer, certify that:

 

1. Ihave reviewed this quarterly report on Form 10-Q of IHS Inc.;

 

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

 

3.Based on my knowledge, the financial statements, and other financialinformation included in this report, fairly present in all material respectsthe financial condition, results of operations and cash flows of the registrantas of, and for, the periods presented in this report;

 

4. Theregistrant’s other certifying officer and I are responsible for establishingand maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) for the registrant and we have:

 

a) designed suchdisclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

 

b) evaluated theeffectiveness of the registrant’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

 

c) disclosed in thisreport any change in the registrant’s internal control over financial reportingthat occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that hasmaterial affected, or is reasonably likely to materially affect, the registrant’sinternal control over financial reporting; and

 

5. Theregistrant’s other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to theregistrant’s auditors and the audit committee of the registrant’s board ofdirectors (or persons performing the equivalent functions):

 

a) all significantdeficiencies and material weaknesses in the design or operation of internalcontrols over financial reporting which are reasonably likely to adverselyaffect the registrant’s ability to record, process, summarize and reportfinancial information; and

 

b) any fraud, whether ornot material, that involves management or other employees who have asignificant role in the registrant’s internal control over financial reporting.

 
| Date:                                | September 30, 2008 |   |
|--------------------------------------|-------------------------|--------|
|                                 |                    |
| /s/ Jerre L. Stead                   |                    |
| Jerre L. Stead                       |                    |
| Chairman and Chief Executive Officer |                    |

 

----