Self-efficacy refers to the belief that one can perform successfully at a given task or endeavor. Previous research indicates that self-efficacy in relation to conventional pursuits (e.g., performance in school) is associated with positive social adjustment. However, the possibility that individuals may develop self-efficacy in relation to nonconventional pursuitsincluding crime and delinquencyremains largely unexplored. In this study, the authors adopt a multimethod approach to explore (a) offenders' personal judgments regarding their level of effectiveness or "success" at crime, (b) the factors that contribute to high criminal self-efficacy, and (c) the impact of self-efficacy judgments on offenders' future intentions. Results of quantitative and qualitative analyses reveal that many offenders maintain a strong sense of criminal efficacy despite past arrests, convictions, and incarceration. Moreover, criminal self-efficacy tends to reduce their intentions to desist from crime. Implications for punishment, deterrence, and criminological theory are discussed. Abstract published by arrangement with Sage Journals.