This study explored (a) the relation of the four hypothesized sources of efficacy information (personal performance accomplishments, vicarious learning, social persuasion, and emotional arousal) to mathematics self-efficacy percepts and (b) the relations among self-efficacy, outcome expectations, interest in mathematics-related college courses, and choice of science-based careers. Subjects were 138 introductory psychology students. Results indicated that the efficacy informational sources were significantly predictive of and helped explain gender differences in mathematics self-efficacy, that outcome expectations complemented self-efficacy in predicting interest and choice indexes, and that the effects of self-efficacy on science-related career choice were mediated by interests. Implications for the further extension of social-cognitive theory to career behavior are discussed.