Rotator cuff tears are a common cause of shoulder pain and disability. Although many studies have reported about the surgical results of full-thickness tears of the rotator cuff, there are few studies about the efficacy of conservative treatment. The aim of this study was to investigate the efficacy of conservative treatment in patients with full-thickness rotator cuff tears by using objective and subjective measurements. Twenty patients with full-thickness rotator cuff tears were included in the study. Outcome measures were range of motion, pain and function according to the shoulder index of the American Shoulder and Elbow Surgeons (ASES), Constant score, Short-Form 36 Health Survey (SF-36), isokinetic shoulder strength, and patient response. Patients were assessed at baseline and after 6 months. In addition, patients were contacted by telephone at 1 year and at 3 years for functional assessment according to ASES, and patient response. The treatment protocol included activity modification, oral nonsteroidal antiinflammatory medications, physical modalities, and a specific exercise program. Statistically significant improvements were obtained in range of motion, pain and function scores according to ASES, Constant score, SF-36 scores, and isokinetic strength (P < 0.05). At the 6-month evaluation, 11 patients (55%) reported that they were "much better", and 9 patients (45%) "better". Conservative treatment of full-thickness rotator cuff tears yields satisfactory results both subjectively and objectively.