We present a series of five patients with quadrilateral space syndrome. All patients had the diagnosis made on the basis of (1) tenderness over the quadrilateral space, (2) paresthesia over the lateral shoulder and upper posterior arm, and (3) deltoid weakness associated with decreased shoulder abduction. A history of trauma was present in each patient. The operative technique described utilizes a cosmetically acceptable incision and is without the need to divide the deltoid from its origin on the scapular spine. The technique minimizes postoperative bleeding and facilities rehabilitation. Arteriography of the posterior circumflex humeral artery was not found necessary to make the diagnosis of axillary nerve entrapment in the quadrilateral space.