We analyzed the cases of thirty-nine patients who were treated for recurrent anterior dislocation of the shoulder after unsuccessful surgical repair for the same condition in order to identify factors responsible for failure of the earlier operations and to determine the results of treatment of the post-surgical recurrence. The prior operations included nineteen Bankart, seven Putti-Platt, five Magnuson, three duToit, two Bristow, and three Nicola procedures. Thirty-two shoulders were treated by reoperation. At reoperation the most common pathological lesion associated with recurrence of the dislocation after the prior repair was a Bankart lesion (avulsion of the capsule and labrum from the anterior glenoid rim). This was present in 84 per cent of the thirty-two shoulders that were treated by reoperation. Excessive laxity of the capsule was found in 83 per cent of the twenty-nine shoulders in which laxity was assessed, and was considered to be the primary cause of instability in four shoulders. A Hill-Sachs lesion of the humeral head was found in 76 per cent of the twenty-nine shoulders that were evaluated for this lesion and was large in three of the shoulders. Other factors that were associated with recurrent instability were scarring of the subscapularis muscle, generalized ligament laxity, technical errors at surgery, and severe reinjury. The success rate of reoperation after previous failure was very encouraging. Of the twenty-four shoulders that were reoperated on and were followed for two years or longer, ten were graded excellent; twelve, good; and two, poor. One (4 per cent) of the twenty-four shoulders that were reoperated on continued to dislocate and another shoulder continued to subluxate, making the incidence of recurrent instability after reoperation 8 per cent. Seven of the thirty-nine shoulders did not have a reoperation but were treated with specific resistive exercises. The results in these were one excellent, four good, one fair, and one poor. Eight patients were lost to follow-up.