Successful outcome of total shoulder arthroplasty depends on a well-designed and a well-executed physical therapy program. For maximal benefit, the program is usually initiated immediately after surgery and follows a logical pattern of joint mobilization followed by muscle strengthening. The process proceeds through a series of well-defined phases. The patient must see himself or herself as the active agent in the program, a concept that is enhanced by a discussion and demonstration of the therapy goals before surgery. Because of a unique understanding of the therapy requirements, the surgeon should remain intimately involved with the patient and therapist, frequently evaluating progress and outcomes of the exercises. When a well-performed surgical procedure is supplemented with a well-designed and frequently monitored therapy program, an excellent outcome of shoulder replacement should be expected.