One-hundred-and-sixty patients with closed traction lesions of the brachial plexus sustained in motorcycle accidents were asked about their accident. One-hundred-and-six responded. Most were young men with limited experience of riding motorcycles. Riders with less than one year's experience were more likely to be injured in the absence of another vehicle than were more experienced riders. Two-thirds of those responding felt the present training requirements for motorcyclists to be inadequate.