The purposes of the work described in this article were to (1) describe a model of predictive relationships among psychosocial variables and lifestyle management, and (2) test the model among people with epilepsy. The variables selected for the model were based on social cognitive theory and the results of previous studies examining psychosocial predictors of self-management among people with chronic physical health conditions. Variables included in the model were self-efficacy, outcome expectancies, depressive symptoms, and social support. Participants for the study were recruited from epilepsy treatment facilities in Boston, MA, and Atlanta, GA, USA. Half of the participants were female, 81% were white, and their mean age was 43.1 years. As predicted by social cognitive theory, self-efficacy was related to lifestyle management and explained 23% of its variation. Depressive symptoms were related to both self-efficacy and social support. Social support was related to self-efficacy. These findings suggest that lifestyle management is influenced by a number of relationships between psychosocial variables, particularly by self-efficacy.