Seventeen children with Erb's (C5/6 and C5/6/7 types) obstetric brachial plexus palsy who underwent low rotation humeral osteotomy to treat internal rotation contracture of the shoulder were recalled back to the clinic at a mean of 10 (range 8-14) years after surgery. Eight were male and nine female with mean age of 16 (range 13-20) years. The osteotomy procedure was done at a mean age of 6 (range 5-8) years. Preoperative, early postoperative, and late postoperative motor assessments were compared. There was no recurrence of the internal rotation posturing of the shoulder and there was maintenance of the improvements in elbow extension deficit and forearm rotation. The most surprising finding was a significant (P = 0.003) decrease in shoulder abduction on long-term follow-up (the mean shoulder abduction was 135 degrees , 146 degrees and 109 degrees measured pre-, early post- and late postoperatively, respectively). There was no correlation between changes in shoulder abduction and the radiological score of the shoulder.