Since 1980, the authors have used a posterior approach to the glenohumeral joint in which the posterior deltoid is split caudally in line with its fibers from the posterior acromion to the upper border of the teres minor. The extent of this deltoid splitting approach exceeds that of a similar anterior approach because of the distal emergence of the axillary nerve from the quadrilateral space. This technique gives complete access to the infraspinatus and teres minor muscles and tendons, posterior capsule, and posterior glenoid. Unlike traditional posterior approaches to the shoulder joint that detach a portion or all of the origin of the deltoid, this technique preserves the deltoid origin from the scapular spine and posterior acromion. Over the past 11 years, this posterior approach has been performed in 35 patients (42 shoulders): 31 for posterior instability, one for posterior glenohumeral fracture-dislocation, eight for infection, and two for removal of foreign bodies. The median age of the patients was 33.8 years (range, 13-65 years). The mean duration of follow-up contact was 20 months (range, one month to 11.4 years). Two patients died of unrelated causes and three were lost to follow-up examination. The posterior deltoid-splitting approach is advocated for any procedure requiring posterior access to the glenohumeral joint because it provides excellent exposure, has been associated with no complications, and preserves the strength and function of the posterior deltoid.