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 will be subsequently asked to provide their evaluations. In a series of field studies, we demonstrate that expecting to evaluate leads to more negative quality and satisfaction evaluations. The negative bias of expected evaluations is observed both when actual quality is low and when it is high, and it persists even when buyers are told explicitly to consider both the positive and negative aspects. We examine three possible explanations for this systematic bias, 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 paper concludes with a discussion of the theoretical and practical implications of this research.