**Exhibit31.1**

**CERTIFICATIONPURSUANT TORULES 13a-14(a) AND 15d-14(a) UNDER THE SECURITIES EXCHANGE ACT OF 1934,AS AMENDEDPROMULGATED UNDERSECTION 302 OF THE SARBANES-OXLEY ACT OF 2002**

I, Christopher B. Wood,certify that:

1.     I have reviewed this annual reporton Form 10-K of Bioenvision, Inc.;

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

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

4.     The registrant’s othercertifying officer and I am responsible for establishing and maintainingdisclosure controls and procedures (as defined in  Exchange  Act Rules  13a-15(e)  and 15d-15(e)) and internal control over financial reporting (asdefined  in  Exchange Act  Rules  13a-15(f) and  15d-15(f))   for the registrant and have:

(a)   Designed such disclosurecontrols and procedures, or caused such disclosure controls and procedures tobe designed under our supervision, to ensure that material information relatingto the registrant, including its consolidated subsidiaries, is made known to usby others within those entities, particularly during the period in which thisquarterly report is being prepared;

(b)   Designed such internal control over financialreporting, or caused such internal control over financial reporting to bedesigned under our supervision, to provide reasonable assurance regarding thereliability of financial reporting and the preparation of financial statementsfor external purposes in accordance with generally accepted accountingprinciples;

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

(d)   Disclosed in this report anychange in the registrant’s internal control over financial reporting (asdefined in Exchange Act Rules 13a-15(f) and 15d-15(f)) that occurred during theregistrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarterin the case of an annual report) that has materially affected, or is reasonablylikely to materially affect, the registrant’s internal control over financialreporting; 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 registrant’s board ofdirectors (or persons performing the equivalent function):

(a)   All significant deficienciesand material weaknesses in the design or operation of internal control overfinancial reporting which are reasonably likely to adversely affect theregistrant’s ability to record, process, summarize and report financialinformation; and

(b)   Any fraud, whether or notmaterial, that involves management or other employees who have a significantrole in the registrant’s internal control over financial reporting.
| Date: September 12, 2007 |
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|                     |   /s/  Christopher B. Wood |   |
|                     | Christopher B.  Wood |
|                     | Chairman and Chief  Executive Officer |

 

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