This article examines the effect of country of origin on the pretrial expectation and the posttrial cognitive and affective attitudes when subjects possess different levels of product expertise. Two experiments with 2 (expert vs. novice) × 2 (Japan vs. Taiwan and Italy vs. Taiwan) factorial designs were conducted. One study was conducted on an unambiguous performance product; the other was conducted on an ambiguous performance product. The results showed that country of origin had an impact on the pretrial expectation in both the novice and expert group, regardless of the ambiguity of the product performance. However, the effects on posttrial attitudes were dissimilar between the expert group and the novice group. © 2003 Wiley Periodicals, Inc.