The two 18-item parallel forms of the Assessment of Body-Image Cognitive Distortions (ABCD; Cash et al., 2004) tap into distorted thinking related to how people process information about their physical appearance. It is based on the theory that people who are disproportionately invested in their appearance process attend to, encode, retrieve, recall, and interpret information in accordance with their appearance-related concerns (e.g., if no one comments favorably on their outfit, they may conclude that it is not flattering). ABCD items are phrased as hypothetical situations and respondents indicate the extent to which each situation is consistent with the mental conversations that they have about their own appearance. The ABCD can be administered online or in-person to adolescents or adults, and it is free to use. This chapter discusses the development of the ABCD and provides evidence of its psychometrics. There is evidence for its unidimensionality. Its internal consistency reliability as well as convergent, concurrent, incremental, and predictive validity. This chapter provides all items, the response scale, and instructions for administering and scoring the ABCD. Logistics of use, such as how to obtain and purchase the ABCD, permissions, copyright, and contact information are available for readers.