Although there have been nearly 20 years of research on self-control theory, the measurement problems of the theory's core construct linger and call into question the efficacy of self-control as a predictor of crime and delinquency. This study assessed the validity of a recently introduced behavioral measure of self-control, the Retrospective Behavioral Self-Control (RBS) measure, which is argued to remedy the conceptual and empirical problems afflicting prior self-control measures. Using a sample of students at a large southern university, this study finds that although a unidimensional and content-valid 18-item RBS measure is not as strong a predictor of crime and delinquency as the original RBS, it has substantially more predictive power than the most commonly used attitudinal measure of self-control, the Grasmick et al. scale. The implications of these findings for empirical tests of self-control theory as well as future directions for the measurement of self-control are discussed. Tables, figures, appendix, and references (Published Abstract)