Injury of the ankle ligaments is one of the most common sports-related injuries. Although there are some debates as to the best initial treatment for an acute tear of a lateral ligament, persistent functional instability of the ankle develops in approximately 20% of patients regardless of the type of initial treatment. In these patients, late reconstruction of the lateral ankle ligaments may become necessary. Among 13 cases which have been operated with Larsen procedure using peroneus brevis tendon from March 1991 to February 1993, the 11 cases followed up over 1 year were examined clinically and radiologically. We introduced the clinical analysis and results with the brief review of the literatures. 1. The indication of surgical treatment was the ankle instability which had differences over 10° in talar tilting angle or over 3mm in anterior displacement compared wit the uninjured site. 2. The postoperative results were 5 cases in excellent and 4 in good. 3. The Larsen procedure was considered a good method to anatomically and simply stabilize both the ankle and subtalar joint and to fix tendon depending on the type of instability.