Theory and empirical research suggest that perceived self-efficacy, or one's perceived ability to perform personally significant tasks, is related to individuals' psychological well-being and mental health. Thus, the authors hypothesized that bicultural individuals' perceived ability to function competently in 2 cultures, or perceived bicultural self-efficacy, would be related positively to their psychological well-being and mental health. Three studies were conducted to develop and validate a measure of perceived bicultural self-efficacy and to explore its relationships with indices of psychological well-being and mental health. Exploratory (n = 268) and confirmatory (n = 164) factor analyses on the theoretically derived Bicultural Self-Efficacy Scale (BSES) items support a measurement model that taps into the 6 dimensions of bicultural competence proposed by T. LaFromboise, H. L. K. Coleman, and J. Gerton (1993). Furthermore, initial evidence for internal consistency (Studies 1, 2, and 3) and test-retest reliability (n = 51 Asian Americans) for each of the 6 subscales were found. Finally, perceived bicultural self-efficacy was found to be related to bicultural college students' psychological well-being and mental health. Research implications of the perceived bicultural self-efficacy construct and the potential utility of the BSES as a multidimensional measure of the construct are discussed. (Contains 1 footnote and 7 tables.)