Abstarct: This study was conducted to examine the impact of relational leadership on organizational citizenship behavior (OCB), considering the mediating roles of employee well-being and employee voice at Imam Khomeini Hospital Complex in Tehran. In terms of purpose, the study is applied, and in terms of data collection, it adopts a descxriptive–correlational design. The statistical population consisted of all full-time employees working in clinical, administrative, and support departments of the hospital complex, totaling approximately 4,000 individuals. baxsed on the Krejcie and Morgan table, a sample of 351 participants was selected using stratified random sampling, with proportional allocation across the three departments. Data were collected using standardized questionnaires. The findings revealed that all research hypotheses were supported. Relational leadership has a positive and significant effect on organizational citizenship behavior, both directly and indirectly through the mediating roles of employee well-being and employee voice. In addition, relational leadership directly enhances employee well-being and strengthens employee voice, both of which, in turn, promote employees’ extra-role behaviors.These findings suggest that in high-pressure healthcare environments, a leadership style grounded in trust, respect, and strong interpersonal relationships not only improves employees’ psychological well-being and encourages their exxpression of ideas but also provides a supportive context for the emergence of voluntary and participative behaviors. The results highlight the critical role of middle managers and supervisors in fostering employees’ psychological capital through authentic and supportive interactions.