The Social Appearance Anxiety Scale (SAAS) was created to measure anxiety about being negatively evaluated by others because of one's overall appearance, including body shape. This study examined the psychometric properties of the SAAS in three large samples of undergraduate students (respective ns = 512, 853, and 541). The SAAS demonstrated a unifactorial structure with high test-retest reliability and internal consistency. The SAAS was positively associated with measures of social anxiety. The SAAS was also related to greater disparity between perceived, actual, and ideal physical attributes, beliefs that one's appearance is inherently flawed and socially unacceptable and that being unattractive is socially deleterious, feelings of unattractiveness, emphasis on appearance and its maintenance, and a preoccupation with being overweight. It was a unique predictor of social anxiety above and beyond negative body image indicators. Findings suggest that the SAAS is a psychometrically valid measure of social anxiety regarding one's overall appearance. (Contains 2 figures, 2 tables and 2 notes.)