Background: Ankle instability is a common consequence of ankle sprains. Injury of the anterior talofibular ligament (ATFL) is the most common cause of ankle instability1. Arthroscopic treatment of ankle instability is an emerging field attracting increased interest among surgeons 2-10 . The arthroscopic all-insideATFLrepair allows the surgeon to explore the ankle joint, treat concomitant pathology when encountered, and reattach the injured ATFL to its fibular anatomical location. The aim of this article is to describe the arthroscopic all-inside ATFL repair through a 3-portal no-ankle-distraction technique. Description: After patient positioning, anteromedial and anterolateral portals are created.Anaccessory anterolateral portal is created just anterior to the fibula and about 1 cmproximal to the tip of the lateral malleolus. The arthroscope is introduced through the anteromedial portal, and the instruments are introduced through the anterolateral portal. Recognition of the ligament and evaluation of the ligament tear with a probe are required. The footprint for the fibular attachment of the ATFL is debrided. The ligament is penetrated with a suture passer. A nitinol loop is pushed and then is pulled out through the accessory portal. The nitinol wire is replaced by a double high-resistance suture. The limbs of the suture located in the accessory portal are passed through the anterolateral portal. Next, one or both limbs of the suture are passed through the loop suture. Pulling of the suture limbs introduces the loop into the joint and the ligament is grasped by the suture. The tunnel for the anchor is drilled. The knotless anchor is loaded with the suture, and the anchor and suture are introduced with the ankle in dorsiflexion and valgus. Postoperatively, the ankle is immobilized with a removable walking boot for 4 weeks. Once use of the walking boot is discontinued, physical therapy is started. Alternatives: Nonoperative treatment with physiotherapy or sports restriction can be an alternative for patients with surgical contraindications or as a first step of treatment. Open techniques (repair or reconstruction) or other arthroscopic-assisted techniques (arthroscopic introduction of anchors and percutaneous passage of sutures, or arthroscopic-assisted reconstruction) are possible surgical alternatives to the described technique to treat ankle instability. Rationale: The described technique has the advantage of being done with a minimally invasive approach and providing an anatomical repair of the ligament. Concomitant intra-articular pathology can be addressed during the procedure through the same arthroscopic approaches. Early rehabilitation and the lack of intra-articular knots are additional benefits of the technique.