Organizational Citizenship Behavior (OCB) has evolved into a critical domain in organizational behavior and human resource management. Emerging in early 1980s, OCB originally referred to discretionary behaviors not recognized directly by formal reward systems but instrumental for organizational efficiency. Over time, its conceptualization, measurement, and practical implications have undergone significant expansion. This paper presents a review of the OCB literature that focuses on its origin, evolution, major contributors, measurement development, antecedents, consequences and emerging research issues. Drawing upon scholarly references, it critically evaluates the body of knowledge and identifies key knowledge gaps and future research directions. This synthesis reveals that while considerable progress has been made in conceptual clarity and measurement, deeper understanding is needed in cross-cultural dynamics, digital environments, and boundary conditions of OCB. This work contributes to the ongoing academic discourse by mapping the trajectory of OCB research and suggesting avenues for further inquiry.
