The purpose of this research is to establish a competencies profile of managers in the public sector, a sector that is not generally focused on competencies approaches. Nevertheless, these could largely, on the one hand, promote modernization of public practices of human resource management and, on the other hand, support them in their relation with the public strategies and the public administration model. The results of this study, realized in Tunisia, show a tension between competencies that we can describe as bureaucratic, with a trend towards vertical relations and compliance with administrative procedures, and other that we can describe as managerial competencies (leadership, communication, vision, management of public policies, etc.). These results indicate that the Tunisian public administration is running toward a new weberian state by trying to reinvent bureaucratic model through adapting it to the challenges of the new public management (Fabian, 2010).