In this study, the psychometric properties of the scenario-based Achievement Guilt and Shame Scale (AGSS) were established. The AGSS and scales assessing interpersonal guilt and shame, high standards, overgeneralization, self-criticism, self-esteem, academic self-concept, fear of failure, and tendency to respond in a socially desirable manner were completed by 322 undergraduate students. A confirmatory factor analysis indicated that a 12-scenario model had an acceptable fit to the data, with guilt and shame items forming separate, weakly correlated subscales. Each of the guilt and shame subscales of the AGSS demonstrated good internal and test-retest reliability. Good construct validity was also evident, with each subscale uniquely correlating with constructs in ways that were consistent with predictions. Acceptable discriminant validity was also evident. These outcomes provide support for the utility of the AGSS in assessing guilt and shame reactions in achievement situations. (Contains 1 figure, 7 tables and 1 note.)