We describe the long-term results in ten patients with obstetric brachial plexus palsy of anterior shoulder release combined with transfer of teres major and latissimus dorsi posteriorly and laterally to allow them to act as external rotators. Eight patients had a lesion of the superior trunk and two some involvement of the entire brachial plexus. The mean age at operation was six years, and the mean follow-up was 30 years. Before operation, the patients were unable actively to rotate the arm externally beyond neutral, although this movement was passively normal. All showed decreased strength of the external rotator, but had normal strength of the internal rotator muscles. Radiologically, no severe bony changes were seen in the glenohumeral joint. No clinically detectable improvement of active abduction was noted in any patient. The mean active external rotation after operation was 36.5 degrees. This was maintained for a mean of ten years, and then deteriorated in eight patients. At the latest follow-up the mean active external rotation was 10.5 degrees. The early satisfactory results of the procedure were not maintained. In the long term there was loss of active external rotation, possibly because of gradual degeneration of the transferred muscles, contracture of the surrounding soft tissues and degenerative changes in the glenohumeral joint.