Exhibit 31.1

CERTIFICATION PURSUANT TO SECTION
302(a) OF THE SARBANES-OXLEY ACT OF 2002

I, G. Patrick Lynch, certify
that:

|1. |  | I have reviewed this quarterly report on
      Form 10-QSB of Northern Technologies International
  Corporation;                                                                                                                                                                                                                                         
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|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;                       
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|3. |  | Based on my knowledge, the financial
      statements, and other financial information included in this report,
      fairly present in all material respects the financial condition, results
      of operations and cash flows of the small business issuer as of, and for,
      the periods presented in this report;                               
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|4. |  | The small business issuers other certifying
      officers 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)) for the small business issuer and have:                                                                                     
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|5. |  | The small business issuers other certifying
      officers and I have disclosed, based on our most recent evaluation of
      internal controls over financial reporting, to the small business issuers
      auditors and the audit committee of the small business issuers board of
      directors (or persons performing the equivalent function):
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|Date: January 11, 2008 |                                         | 
|---------------------- | --------------------------------------- | 
|                       | G.
      Patrick Lynch                 
|                       | President and Chief Executive
  Officer

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