One of the examples of behavioral patterns of employees is positive extra role behaviors. The purpose of this study is to determine the direct and indirect effects of contextual and attitudinal factors by focusing on organizational citizenship, which is one of those behaviors. The data which were collected from 384 employees of a private bank by using a survey form including Organizational Citizenship Behaviors Scale, Organizational Culture Scale and Organizational Commitment Scale were analyzed with structural equation modeling technique. The findings of this study indicate that the clan and development tendencies predict conscientiousness and courtesy, and the development tendency predicts sportsmanship and civic virtue behaviors of the employees’ extra role behaviors. Moreover organizational commitment has a partial mediator role in all these processes.