Abbott (1988) suggested that a sociological theory of professions involved considering professions not in isolation but as parts of a broader system of professions. From this perspective, expansive or contracting forces at play for one profession will produce expansions or contractions in others. Globally, it is challenging to identify the claims for jurisdiction within which the profession of physical education operates, due in large part to the many other forces and professions that influence its work, professional knowledge, structures, and audiences. In this presentation I will use the physical education profession in Ontario as a case to consider its jurisdictional claims as well as major influences from the professional system it is nested within. A potential recent force impacting on the jurisdiction of physical education in Ontario is the establishment of the kinesiology profession, which is in turn strongly influenced by the medical and health professions. A major point of analysis and discussion in the presentation will be dedicated to considering how the jurisdictional claims of kinesiology might influence and shape the audiences, professional knowledge, and ongoing professionalization of physical education in the coming years, particularly in terms of how these will influence the professionalization processes of physical education processes in universities.