The purpose of the study described in this article was to evaluate the extent to which selected behavioral, social, and affective factors contribute to self-reported epilepsy self-efficacy. Participants completed three assessments 3 months apart, with only those completing both the first and second assessments included in this analysis. Self-efficacy scores at the second assessment were regressed on the behavioral, social, and affective characteristics ascertained at the first assessment. The analysis revealed that self-management, depressive symptoms, and seizure severity explain the most variance in self-efficacy; patient satisfaction and stigma are less important predictors; and social support and regimen-specific support are not significant predictors. The results provide direction for identifying people with low levels of self-efficacy and highlighting areas that might help enhance self-efficacy in persons with epilepsy.