This study aims to examine the role of the double mediation of cognition-based trust and affect-based trust, along with the quality of the exchanges (perceived organi­zational support/POS and leader-member exchange/LMX), on the influence of organi­zational justice on organizational citizenship behavior (OCB). The survey involved 182 contract lecturers from the five top Muhammadiyah universities in Indonesia. Using structural equation models, this study has succeeded in demonstrating that the quality of the individual exchanges between supervisors and subordinates (LMX and affective-based trust) successfully mediate the sources of justice from the supervisors (interactional and informational justice). The quality of the individual exchanges with organizations (cogni­tive-based trust and POS) successfully mediate the sources of the organization (procedur­al justice). Implications for the theory and practice are discussed.