We assessed the long-term outcome of open debridement for the treatment of anterior impingement of the ankle in 27 patients. By using preoperative radiographs to group patients according to both the McDermott and the van Dijk scoring system, we assessed the accuracy of these classifications in predicting outcome. The Ogilvie-Harris scoring system, a visual analogue scale of patient satisfaction, the time to return to full activities, and the ability to return to sports determined the clinical outcome. Follow-up radiographs were used to assess the recurrence of osteophytes. We also assessed the incidence of talar osteochondral lesions at surgery. At a mean follow-up of 7.3 years, 23 of 25 patients (92%) without joint-space narrowing had a good or excellent result. Improvement in the Ogilvie-Harris score was seen in all patients. In athletes, 19 of 24 (79%) were able to return to sports at the same level. Two patients with preoperative joint-space narrowing had a poor result. Osteophytes usually recurred and most patients did not feel that the range of dorsiflexion returned to normal, but symptomatic relief allowed most to return to high-level sport. Our results for non-arthritic joints suggest that this is a safe and successful procedure