Internal marketing tries to satisfy needs of employees by considering them as the organization's internal market. According to performed researches satisfaction of the organization's employees needs in the best manner through internal marketing activities could be leaded to forming and improving of employees' extra-role behaviors in addition to improvement of their in-role behaviors. Organizational citizenship behaviors are one of the extra-role behaviors of employees in the organization. Thus, the present survey examines the relationship between internal marketing and organizational citizenship behavior and the impact of internal marketing dimensions on the amount of appearing of employees' citizenship behavior. Population of this research includes employees of Melli Bank in Isfahan city of Iran. after sampling of 220 persons, Questionnaire is used for data collection. Two-hundred fifteen (215) returned questionnaires have been analyzed. Structural equations technique and path analysis (regression model) have been used to test hypotheses by applying of Amos Graphic software. Results showed that all five hypotheses are accepted with 95% confidence.