Farajnia, S - Dr Hoseinian, S - Dr Shihidi, SH - Dr Sadeghi, M The goal of present study was to examine the role of sexual function and quality of relationship on marital commitment. The sample included 115 couples. The research instruments were Quality of Marital Relationship Questionnaire, Marital Commitment Questionnaire and Marital Sexual Function Questionnaire. Data were analyzed by correlation coefficient and step by step multiple regression method. Results showed significant relationships between sexual function, quality of relationship and marital commitment. According to the results, sexual function and quality of relationship predicted marital commitment and quality of relationship was a stronger predictor of marital commitment. Through Components of Sexual Function and Quality of Relationships, the only Sexual Realization and Communication Styles have predicted the roles for the Marital Commitment. The Significant relationships were found between wives 'commitment with their sexual function, their husbands 'commitment and sexual function, and husbands 'commitment with their wives 'commitment and their sexual function.