The purpose of this thesis is to examine which are the core competencies for project managers and how competencies differ between software project man-agers and general project managers. This thesis has two parts, the literature re-view and the empirical study. First the most important concepts are defined: project, project manager, project management, competence/competency. Then the literate review is presented which includes researches and their results, and framework of core competencies for project manager. The empirical study con-sists with the description of research method and results. The empirical study was conducted with qualitative research and the research data was collected by half-structured theme interview which was analyzed using data and theory driven content analysis. The literate review and the empirical study results were quite similar, especially when observed from framework or single compe-tency point of view. While the subject was studied deeper, results showed that domain specific competencies are the most significant factors how software project manager competency demands differ from general project manager competency demands.