Nowadays, there is no need to say that organizational effectiveness is important. In todays competitive world, consultants and academics propose new bases to enhance the effectiveness and performance of organizations. In this paper, we have used two new approaches which have found significant emphasis from the part of researchers: organizational capabilities and managerial competencies. This paper aims to evaluate the effects of managerial competencies and organizational capabilities on the organizational effectiveness. This study develops an integrated model to be tested. The survey data have been collected from 58 managers in all levels of four companies. The results show that the proposed model significantly explains the variance of organizational effectiveness. Findings reveal that both organizational capabilities and managerial competencies contribute significantly to enhancing organizational effectiveness, although the effect of organizational capabilities on organizational effectiveness is more than that of managerial competencies.