Thirty-five shoulders in thirty-four patients were treated with a superior shift of the posteroinferior aspect of the capsule because of recurrent posterior glenohumeral subluxation and dislocation. The physical examination revealed three types of posterior instability in these patients preoperatively: unidirectional (six shoulders), bidirectional (posterior and inferior) (seven shoulders), and multidirectional (posterior and inferior dislocation with anterior subluxation) (twenty-two shoulders). Eleven shoulders had had previous operative procedures. At the time of the index operation, the most common abnormal findings in these shoulders were capsular redundancy and excessive volume of the glenohumeral joint. Complete detachment of the posterior aspect of the labrum was found in only four shoulders. There was no excessive glenoid retroversion in these patients. All thirty-four patients were available for follow-up at an average of five years (range, two to twelve and a half years) postoperatively. Over-all, the result for seventeen of the thirty-five shoulders was rated as excellent; eleven, as good; one, as fair; and six, as poor. Four shoulders became unstable again. Six of the seven unsatisfactory results were in shoulders that had had previous attempts at stabilization. A successful result was achieved in twenty-three of the twenty-four shoulders in which the superior shift of the posteroinferior aspect of the capsule was the initial repair.