The purpose of this study was to examine the impact of the leadership of social welfare organization managers on the organizational citizenship behavior of social workers in an attempt to help facilitate the efficient management of social welfare organizations. The subjects in this study were 215 social workers in social welfare centers, on whom a survey was conducted. The collected data were analyzed, and the findings of the study were as follows: First, as for the general characteristics of the social workers investigated, most of them were female and college graduates. And the majority of the rank-and-file social workers were second-grade certified social workers. Second, in regard to the influence of leadership by gender, the male social workers were under the greater influence of conditional reward and transactional leadership. By academic credential, the junior-college graduates were more affected by leadership than the college graduates. By certificate, the second-grade social workers were more impacted by transactional leadership and exceptional management, part of transactional leadership. By position, the senior social workers and team leaders were under the larger influence of exceptional management, individual care and transformational leadership than the rank-and-file social workers. By the length of service, the social workers who worked for four to less than seven years were more sensitive to transformational leadership involving charisma and inspiration. Third, in terms of organizational citizenship behavior, the male social workers behaved in a more autonomous manner at their workplaces than the females. The second-grade social workers were more loyal, and those of a higher position behaved in a more autonomous way. Those who worked for fewer years were more altruistic. Fourth, concerning the impact of leadership on organizational citizenship behavior, altruistic behavior was more prevailing when more conditional reward, individual care and intellectual stimuli were provided. A supply of more conditional reward and intellectual stimuli led to more conscientious behavior, and self-development behavior was more common when more individual care and intellectual stimuli were offered. Interpersonal behavior was more dominant when more conditional reward and intellectual stimuli were supplied, and more charisma and intellectual stimuli were followed by loyal behavior. And there was better organizational citizenship behavior when more conditional reward and intellectual stimuli were offered. Given the findings of the study, there are some suggestions: First, managers of social welfare organizations should exert the best leadership in light of organizational characteristics, and efficient human resources management is required by providing reasonable reward and psychological backing. Second, the managers should clarify the objectives of their organizations to make the members more community-minded, and improve their leadership in accordance with the given situations. Third, the managers should try to build an amicable relationship with the organizational members and acquire profound and extensive professional knowledge to provide full-fledged intervention in pursuit of successful problem solving. Finally, future research efforts should be channeled into examining multiple variables related to the organizational efficiency of social welfare organizations and suggesting how to ensure the successful management of the organizations.