The purpose of this study is to evaluate the objective, subjective, and radiographic results of arthroscopic biceps tenotomy in selected patients with rotator cuff tears. Three hundred seven arthroscopic biceps tenotomies were performed in patients with full- thickness rotator cuff tears. Patients were selected for arthroscopic tenotomy if the tear was thought to be irreparable or if the patient was older and not willing to participate in the rehabilitation required after rotator cuff repair. Patients were evaluated clinically and radiographically at a mean of 57 months' follow-up (range, 24-168 months). The mean Constant score increased from 48.4 points preoperatively to 67.6 points postoperatively ( P < .0001). Eighty-seven percent of patients were satisfied or very satisfied with the result. The acromiohumeral interval decreased by a mean of 1.3 mm during the follow-up period and was associated with a longer duration of follow-up ( P < .0001). Preoperatively, 38% of patients had glenohumeral arthritis; postoperatively, 67% of patients had glenohumeral arthritis. Concomitant acromioplasty was statistically associated with better subjective and objective results only in patients with an acromiohumeral distance greater than 6 mm. Fatty infiltration of the rotator cuff musculature had a negative influence on both the functional and radiographic results ( P < .0001). Arthroscopic biceps tenotomy in the treatment of rotator cuff tears in selected patients yields good objective improvement and a high degree of patient satisfaction. Despite these improvements, arthroscopic tenotomy does not appear to alter the progressive radiographic changes that occur with long-standing rotator cuff tears.