BACKGROUND Symptomatic pan-labral or circumferential (360 degrees ) tears of the glenohumeral labrum are an uncommon injury. The purpose of the present study was to report the results of surgical treatment of circumferential lesions of the glenoid labrum with use of validated outcome instruments. METHODS From July 2003 to May 2006, forty-one shoulders in thirty-nine patients (thirty-four men and five women) with a mean age of 25.1 years were prospectively enrolled in a multicenter study and were managed for a circumferential (360 degrees ) lesion of the glenoid labrum. All patients had a primary diagnosis of pain and recurrent shoulder instability, and all underwent arthroscopic repair of the circumferential labral tear with a mean of 7.1 suture anchors. The outcomes for thirty-nine of the forty-one shoulders were assessed after a mean duration of follow-up of 31.8 months on the basis of the rating of pain and instability on a scale of 0 to 10, a physical examination, and three outcome instruments (the Single Assessment Numeric Evaluation score, the modified American Shoulder and Elbow Surgeons score, and the Short Form-12 score). RESULTS Significant improvement was noted in terms of the mean pain score (from 4.3 to 1.1), the mean instability score (from 7.3 to 0.2), the mean modified American Shoulder and Elbow Surgeons score (from 55.5 to 89.6), the mean Short Form-12 score (from 75.7 to 90.0), and the mean Single Assessment Numeric Evaluation score (from 36.7 to 88.5). Six shoulders required revision surgery because of recurrent instability (two), recalcitrant biceps tendinitis (two), or postoperative tightness (two). All patients returned to their preinjury activity level. CONCLUSIONS Pan-labral or circumferential lesions are an uncommon yet extensive injury of the glenohumeral joint that may result in recurrent instability and pain. The present study demonstrates that arthroscopic capsulolabral repair with suture anchor fixation can restore the stability of the glenohumeral joint and can provide a reliable improvement in subjective and objective outcome measures.