In the hands of bowlers, a traumatic neuroma of the digital nerve on the web side of the thumb may develop in association with fibrosis of the regional tissue. This condition may cause permanent disability if it is not diagnosed and treated early. Surgery can be of assistance when the symptoms are severe and intractable. However, if the condition is severe, surgery will probably never completely restore the thumb to normal. Therefore, early recognition and the prompt use of appropriate protective measures are important. The condition may be aggravated by changes in the local tissues, including tumors adjacent to the nerve. Presently, neither bowlers nor physicians are sufficiently aware of this serious problem, and its incidence is unknown.