Organizational citizenship behavior (OCB) is a form of positive, constructive and meaningful social behavior that helps the tasks given by the leadership become lighter if there are workers with high OCB and that the consequences will increase productivity and success which can be seen as a factor that contributes to the work of the company. This study aims to examine the leadership and quality of worklife on organizational citizenship behavior mediated by job satisfaction at PT. Pertamina (Persero). The sampling technique used by re-searchers is proportional random sampling. In this study, there are 359 employees working for this firm where 217 people are the employees of PT. Pertamina (Persero) MOR III Jakarta and 142 are working for MOR V Surabaya. The sample of respondents used in this study are 189 people. The procedure used in testing, data processing and model development is a structural equation model. Data are analyzed using SMART-PLS tools. The results indicate that there is a positive direct effect of leadership on job satisfaction, there is a positive direct effect of quality of worklife on job satisfaction, there is a positive influence of leadership on OCB, there is a positive direct effect of quality of worklife on OCB, there is a positive direct effect on job satisfac-tion on OCB, there is a positive indirect effect between leadership and OCB through job satisfaction, and there is a positive indirect effect between quality of worklife and OCB through job satisfaction.