Acute ankle sprains are among the most common musculoskeletal injuries. If left unrecognized and/or undertreated, this may lead to chronic ankle instability (CAI) with significant and long-lasting consequences for the ankle joint. The anterior talofibular ligament (ATFL) is injured in more than 70% of all ankle sprains, while the deltoid ligament is involved <3%. Medial ankle pain in the context of CAI is related to antero-medial impingement and not to medial laxity. Well-performed non-surgical treatment provides favorable outcomes in most cases of acute ankle sprain. Around 20% of patients, however, will experience symptomatic lateral CAI, dominated by recurrent instability, repeated episodes of ankle sprains, and significant limitations in functional activities. Most of these patients can successfully be treated with rehabilitation. In case of failure of non-surgical treatment, patients may require surgical treatment. In elite athletes, the acute surgical treatment has been increasingly proposed since this provides a more stable ankle and will reduce the recurrence rate in this high-demand population. In its many modifications, the “classical” surgical repair by anatomic reconstruction has achieved good results over the years. Particularly in the last decade, there has been growing interest in arthroscopic repair of ankle instability and has provided good outcomes while also enabling the treatment of other concomitant lesions. This chapter provides a detailed description of four different arthroscopic anatomic techniques.