The question of project manager competencies and especially in social projects is a key issue for social organizations seeking to progress and achieve success. If the manager has an important role to play with regard to the social organization, he’s however dependent on his behavioral, professional and personal capacities. The purpose of this paper is to show, on the basis of a quantitative study carried out among 120 managers of social projects in cooperatives located in the city of Agadir (Morocco), that the success of projects is conditioned by the leadership skills. Consequently, factors related to behavioral skills such as Solidarity; Involvement; Patience; Creativity; Empathy; Motivation; Trust; Commitment; Self-esteem; Transparency; Self-control; Discipline and other factors related to professional characteristics and personal characteristics of project managers prove a positive and significant relationship with the criterion of success studied.
