This article argues that although occupational therapy and rehabilitation are often considered synonymous, the latter is but one aspect of the former. Early influences on occupational therapy are briefly reviewed, and some philosophical ideas about activity are described. The rationale for the use of occupations as treatment in the early part of this century, both in Canada and in the United States, is examined and contrasted with the development of physical medicine and rehabilitation after World War II. This discussion demonstrates that the origins of occupational therapy and rehabilitation in North America had little in common. As occupational therapy became incorporated into rehabilitation, the profession’s core values eroded, and although current definitions of rehabilitation offer a more appropriate fit for occupational therapy, rehabilitation continues to see engagement in occupations as a separate and subsequent step. The article concludes by considering future directions and the tasks that lie ahead.