A two-part study examined the effects of leadership efficacy and optimism on the evaluation and performance of military cadet leaders. Cadets at several universities responded to measures of leadership confidence and optimism. In Part 1, the cadets (n = 96) were rated for leadership potential by their military science professors. Both leadership efficacy and optimism were associated with rated leadership potential. Part 2 followed most of the same cadets (n = 64) to U.S. Army summer leadership training. Leadership efficacy, but not optimism, was strongly related to performance evaluations by objective observers in a leadership simulation and to leadership ratings by peers and superiors. A measure of general self-esteem was not an independent predictor of leadership performance ratings, and neither leadership efficacy nor optimism predicted nonleadership performance measures. These findings suggest that self-rated leadership efficacy has concurrent, predictive, and discriminant validity as a contributor to leadership evaluations.