Labral tears and associated glenohumeral ligament injuries were classified and treated arthroscopically in 83 patients. Transverse labral tears were the most common. Subtle increased glenohumeral translation was noted in 24% of patients. Glenohumeral ligament injury was present in 58% of the shoulders, with the middle and superior ligaments or middle ligaments alone most commonly involved. These ligament injuries were classified into different groups based on severity. Partial excision of the torn labrum was the primary treatment in all patients and was combined with glenohumeral ligament repair in 9 patients. Seventy-eight patients were available for subjective follow-up evaluation (average, 3.2 years), while 53 patients were objectively evaluated (average followup, 2.8 years). There were 14% excellent, 71% satisfactory, and 15% poor results. The main factor associated with poor results was a grade III glenohumeral ligament injury in which only partial excision of the torn labrum was performed. There was a positive correlation between injury to both the superior and middle glenohumeral ligaments and increased anterior translation demonstrated by preoperative stability testing at 60 degrees of humeral abduction in neutral rotation. We believe glenohumeral ligament injury is often associated with labral tears and arthroscopic partial labral excision is only effective in those patients who have grade I or II (less severe) glenohumeral ligament injuries.