A 12-item self-report scale was developed to assess the degree to which people become anxious when others observe or evaluate their physiques. The Social Physique Anxiety Scale (SPAS) demonstrated both high internal and test-retest reliability. It also correlated appropriately with concerns regarding others' evaluations and with feelings about one's body. Validity data showed that women who scored high on the SPAS were heavier and had a higher percentage of body fat than those who scored lower. In addition, high scorers reported significantly greater anxiety during a real evaluation of their physiques, further supporting the validity of the scale. Possible uses of the SPAS in basic research involving physique anxiety and in applied fitness settings are discussed.