Isolated ankle syndesmosis disruption (without fibula fracture) causes acute pain and may cause chronic instability and pain. The aim of the present study was to evaluate the outcomes after anterior inferior tibiofibular ligament (AITFL) anatomical fixation using anchor sutures for unstable isolated syndesmosis disruption without fibular fractures. This study assessed 22 athletes who were diagnosed with unstable isolated syndesmosis disruption with a positive external rotation test, had more than 2-mm diastasis on ultrasound, and had complete AITFL rupture on magnetic resonance imaging between 2004 and 2020. Eighteen patients (82%) were elite-level athletes, and the remaining 4 were recreational athletes. Twelve patients (55%) were injured by an external rotation force. The athletes underwent open anatomical suture anchor fixation between the AITFL attachment sites, the fibula and tibia. The mechanism of injury, return-to-play time, and Foot and Ankle Outcome Score (FAOS) were evaluated. All athletes returned to previous play except 1 retired elite athlete. Twenty-two athletes returned to jogging, team training, and official game play at an average of 62, 89, and 102 days, respectively. The final average follow-up FAOS symptom, pain, daily activity, sports activity, and quality of life scores were 98, 97, 100, 99, and 97, respectively. Two athletes were reinjured, and 1 required reoperation in the follow-up period. Athletes with isolated syndesmosis disruption had a high likelihood to return to their previous activity level after suture anchor augmentation. Level IV, case series.