The project management literature on project success is rich. Numerous papers focus on the evolution of the understanding of project success, identification of success criteria and critical success factors. Critical success factors increase the potential for achieving project success, while project success can be evaluated with the help of success criteria. Although the interrelationships between critical success factors and success criteria are rarely analyzed, yet there is a strong demand for it. The aim of this paper is twofold. One of the aims is to identify the impact of one of the critical success factors, the project manager’s project management attitude on project success. The other aim is to highlight the interrelationship between the project manager’s personal characteristics and project management attitude and leadership style, which are three critical success factors. These aim to address the shortcoming mentioned above, which is considering the lack of the interrelationships between critical success factors and success criteria. The research outcomes are drawn from qualitative field research at the Hungarian subsidiaries of multinational companies operating in the ICT sector.