This article analyzes organizational functioning from the perspective of social cognitive theory, which explains psychosocial functioning in terms of triadic reciprocal causation. In this causal structure, behavior, cognitive, and other personal factors and environmental events operate as interacting determinants that influence each other bidirectionally. The application of the theory is illustrated in a series of experiments of complex managerial decision making, using a simulated organization. The interactional causal structure is tested in conjunction with experimentally varied organizational properties and belief systems that can enhance or undermine the operation of the self-regulatory determinants. Induced beliefs about the controllability of organizations and the conception of managerial ability strongly affect both managers' self-regulatory processes and their organizational attainments. Organizational complexity and assigned performance standards also serve as contributing influences. Path analyses reveal that perceived managerial self-efficacy influences managers' organizational attainments both directly and through its effects on their goal setting and analytic thinking. Personal goals, in turn, enhance organizational attainments directly and via the mediation of analytic strategies. As managers begin to form a self-schema of their efficacy through further experience, the performance system is regulated more strongly and intricately through their self-conceptions of managerial efficacy. Although the relative strength of the constituent influences changes with increasing experience, these influences operate together as a triadic reciprocal control system.