This study examined the influence of affectively-based weight prejudice versus weight control beliefs on perceptions of and support for an ambiguously discriminatory medical policy: denying surgery to overweight patients. Participants read a news article describing a new policy in the United Kingdom of denying surgery to overweight patients, and reported their reactions to the policy. Results revealed that participants who scored higher on an affectively-based measure of weight prejudice that was completed 3–4 weeks before the main session were less likely to perceive the medical policy as discriminatory, more likely to agree with the policy and to support adoption of a similar policy in their own country, and recommended lower body mass index (BMI) cutoff values for denying surgery to overweight patients, whereas weight control beliefs had less of a role to play. In addition, perceptions of the policy as (non)discriminatory mediated the effects of weight prejudice on policy agreement, support, and recommended BMI cutoff. These results indicate that affective prejudice influences individuals' support for an ambiguously discriminatory medical policy, which has important implications for policy makers and researchers.