In the middle of the twentieth century, the role of occupational therapy assistant was introduced in North America. Although the role, utilization and training of assistant personnel have raised much controversy and debate within the profession, Canada and the United States have taken very different paths in terms of dealing with these issues. This paper focuses on the history of occupational therapy assistants in Canada, using the experience in the United States for comparison purposes. The occupational therapy literature and official documents of the professional associations are used to present a chronology of major historical events in both countries. Similarities and differences emerge in relation to historical roots; training model and standards of education; certification, regulation, and standards of practice; career laddering and career mobility; and professional affiliation. The paper concludes with a summary of issues which require further exploration, debate and resolution if the profession is to move forward in Canada.