Four obese patients who had atrophic synovial non-union of the humeral shaft were treated with a medial approach, application of a plate anteriorly, a vascularized fibular bone graft, and cancellous grafts from the iliac crest. The average age of the patients was forty years; the average weight, 105 kilograms (232 pounds); and the average duration of the non-union, 33.5 months. Each patient had had one to five unsuccessful previous operations in an attempt to gain union. At an average follow-up of twenty-seven months, all four non-unions had healed. Three patients had regained full function of the shoulder and elbow, and the fourth patient had some limitation of motion of the shoulder due to an antecedent lesion of the rotator cuff. In one patient, a second plate had been applied because of inadequate fixation of the original plate proximally. Another patient had a superficial, partial wound slough, which healed spontaneously.