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