Current theories propose that professional competence is primarily constituted by scientific and tacit knowledge, knowing-in-action, understanding of work or practice. While providing valuable insights we contend that they present a fragmented understanding of professional competence. In particular, they do not adequately explain how central aspects of practice such as knowledge and understanding are integrated into a specific professional competence in work performance. An existential ontological perspective is proposed as offering a more comprehensive and integrative analysis of professional competence. It is explored through an empirical study of corporate lawyers and the findings suggest that professional competence should be understood as ways of being. The results show that different ways of practising corporate law distinguish and integrate a specific understanding of work, a particular self-understanding, other people, and tools into distinct forms of competence in corporate law.