AbstractThe importance of the inner world of the patients in occupational therapy has not been studied in recent occupational therapy literature. The activity process in this paper is seen as a complex mixture of internal and external transformations which occur as part of the patient's relationship with the therapist. Pertinent psychoanalytic theories are reviewed and their usefulness to occupational therapy is described. Specific sequences of therapy sessions in two case examples are presented to illustrate the dynamics of the relationship of patient, therapist and activity, and to start to identify inner transformations during activity participation. The authors consider basic research on the meaning of activity as a fundamental part of the profession.