Discusses conceptual and empirical issues concerning the relations between moral reasoning and moral action. Two opposite views of the relations between moral cognition and moral action are described; one is an essentially irrational view that emphasizes need and action tendencies, while the other considers moral functioning as essentially rational. Their contrasting assumptions and implications are clarified. Available empirical literature is reviewed; research relating moral reasoning to delinquency, honesty, altruism, conformity, and other real-life moral behaviors is summarized, with special attention given to problems of design, measurement, and interpretation. Although overall these studies seem to support the cognitive–developmental perspective, this support needs to be qualified and interpreted in each area. At a more general level, the importance of clarifying the meaning of consistency between moral cognition and moral action and the need for a process approach to research in this area are emphasized.