**EXHIBIT 31.2**

 

**CERTIFICATION OF CHIEF FINANCIAL OFFICER OFTHE REGISTRANT,PURSUANT TO 17 CFR 240.13a – 14(a) OR 17 CFR 240.15d – 14(a)**

 

I,Ray E. Schmitz, certify that:

 

1.                                       I have reviewed this quarterly report on Form 10-Qof Dynamex Inc.;

 

2.                                       Based on my knowledge, this report does notcontain any untrue statements of a material fact or omit to state a materialfact necessary to make the statements made, in light of the circumstances underwhich such statements were made, not misleading with respect to the periodcovered by this report;

 

3.                                       Based on my knowledge, the financialstatements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operationsand cash flows of Dynamex Inc. as of, and for, the periods presented in thisreport.

 

4.                                       The registrant’s other certifying officer andI are responsible for establishing and maintaining disclosure controls andprocedures (as defined in Exchange Act Rules 13a-15 and 15d-15(e)) for theregistrant and we have:

 

a.                                       Designed such controls and procedures, orcaused such disclosure controls and procedures to be designed under oursupervision, to ensure that material information relating to the registrant,including its consolidated subsidiaries, is made known to us by others withinthose entities, particularly during the period in which this report is beingprepared;

 

b.                                      Evaluated the effectiveness of the registrant’sdisclosure controls and procedures and presented in this report our conclusionsabout the effectiveness of the disclosure controls and procedures, as of theend of the period covered by this report based on such evaluation, and

 

c.                                       Disclosed in this report any change in theregistrant’s internal control over financial reporting that occurred during theregistrant’s most recent fiscal quarter that has materially affected, or isreasonably likely to materially affect, the registrant’s internal control overfinancial reporting;

 

5.                                       The registrant’s other certifying officer andI have disclosed, based on our most recent evaluation of internal control overfinancial reporting, to the registrant’s auditors and the audit committee ofregistrant’s board of directors;

 

a.                                       All significant deficiencies and materialweaknesses in the design or operation of internal controls which couldadversely affect the registrant’s ability to record, process, summarize andreport financial information; and

 

b.                                      Any fraud, whether or not material, thatinvolves management or other employees who have a significant role in theregistrant’s internal controls over financial reporting.

 

 
| Date:               | June 7,  2005                          |   |
|---------------------|---------------------------------------------|--------|
|                |                                        |
|                |                                        |
| /s/  Ray E. Schmitz |                                        |
| Name:               | Ray  E. Schmitz                             |
| Title:              | Vice  President and Chief Financial Officer |
|                     |                                             |        |  |

 

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