The purpose of this paper is to empirically test the impact of governance mechanisms on corporate performance. We have to do this, base our study on two particular mechanisms, namely the ownership structure, through the concentration of ownership and the nature of certain shareholders, and the board of directors characterized by its size and degree of its independence. Based on a sample of 49 Moroccan companies listed during the period from 2008 through 2015, the results of a multiple linear regression show that, apart from the institutional property, the other attributes of the ownership structure and the council of administration do have the positive effect assumed by our predictions.