Twenty-nine patients with non-union of the humeral shaft, who were treated in 3 major Vancouver hospitals, were studied. Reasons for non-union, effectiveness of various treatment methods, and complications are discussed. Fractures occurring in the middle third of the humeral shaft, comminuted or open fractures and those treated early by open reduction, are more prone to non-union. Nearly 50% of the patients with non-union were chronic alcoholics. Compression plating with cancellous bone grafting gave the best rate of healing. However, both early and late operative treatment gave a relatively high complication rate.