Nineteen patients suffering from chronic post-traumatic instability at the ankle were treated surgically by the Chrisman-Snook technique. Mean follow-up time was 38 months. Each patient reported an initial major inversion trauma, followed by repetitive sprains resulting in apprehension, giving way, pain, and swelling at the ankle. Before surgery all patients engaged in sports were obliged to modify or even stop their activities for reasons related to their ankle problem. After reconstruction instability was abolished in all cases and an excellent or good result was obtained in 18. The three top sportsmen included in our series were all able to return to their pre-injury level of sport without any restrictions. A careful dissection of the branches of the sural nerve is considered to be essential, since postoperative paresthesia or numbness over the sural nerve region was found in six cases. This study confirms the efficacy of the Chrisman-Snook technique in the treatment of ankle instability, even in cases of gross ankle laxity or with patients engaged in very demanding sports.