Customers' evaluations of quality and satisfaction are critical inputs in the development of marketing strategies. Given the increasingly common practice of asking for such evaluations, buyers of products (e.g., cars) and services (e.g., hotels, educational programs/courses) often know in advance that they subsequently will be asked to provide their evaluations. In a series of field and laboratory studies, the authors demonstrate that expecting to evaluate leads to less favorable quality and satisfaction evaluations and reduces customers' willingness to purchase and recommend the evaluated services. The negative bias of expected evaluations is observed when actual quality is either low or high, and it persists even when buyers are told explicitly to consider both the positive and negative aspects. The authors examine three possible explanations for this systematic bias, which are referred to as negativity enhancement, role expectation, and vigilant processing. The findings are most consistent with the negativity enhancement account, indicating that unless buyers begin the evaluation task with low expectations, they tend to focus during consumption primarily on negative aspects of product/service quality. The article concludes with a discussion of the theoretical and practical implications of this research.