The purpose of this essay is to study how and why the profession of occupational therapist evolved and what role their association played in 1944-1964. During the first decades of the post-war period, Swedish health care system grew. In particular, rehabilitation health care was developed, in which occupational therapy has a key role. The association of occupational therapists, FAST and later FSA, initially promoted the general development of the area, but after a few years it put more emphasis on the professional perspective itself. Other related professions had developed through the "exclusion" of competing groups in line with sociologist Frank Parkin's theory. However, in this study I find no evidence of FAST/FSA applying that method.  On the basis of empirical sources, such as the Association's meeting minutes, government committee reports, newspaper articles, personal notes, documents from the international organization WFOT's congresses, I describe how FAST/FSA and other key players acted during the studied period. FAST/FSA organized courses, began publishing a member paper, and built a reference library, but also lobbied with the purpose to establish the profession.  After a few years, FSA was expelled from the international organization of occupational therapists, WFOT, whose purpose was to develop the profession internationally by creating a standard of education. Sweden’s education did not meet that standard. After several government committee reports, it was only with a report in 1962 followed by a bill and parliamentary decision in 1964 that education of an acceptable standard was established. Thus, an important prerequisite was in place to regard occupational therapists as a profession in Sweden according to sociologist Magali Sarfatti Larsson's definition.