EXHIBIT 23

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors
Smithway Motor Xpress Corp:

We consent to incorporation by reference in the Registration Statements (Nos.
333-10249, 333-10251, 333-21253, 333-81855, 333-97195 and 333-126026) on Form
S-8 of Smithway Motor Xpress Corp. of our report dated February 10, 2006,
relating to the consolidated balance sheets of Smithway Motor Xpress Corp. and
subsidiaries as of December 31, 2004 and 2005, and the related consolidated
statements of operations, stockholders' equity, and cash flows for each of the
years in the three-year period ended December 31, 2005, which report appears in
the December 31, 2005 annual report on Form 10-K of Smithway Motor Xpress Corp.

                                       /s/ KMPG LLP

Des Moines, Iowa
March 24, 2006