1 EXHIBIT 23.1 INDEPENDENT AUDITOR'S CONSENT We consent to the incorporation by reference in Registration Statement No. 333-07377 of PIA Merchandising Services, Inc. on Form S-8 of our report dated February 18, 1999 appearing in this Annual Report on Form 10-K of PIA Merchandising Services, Inc. for the year ended January 1, 1999. Deloitte & Touche LLP Costa Mesa, California March 26, 1999