Abstract: Objective: The aim of this case report was to demonstrate physiotherapy results of a patient undergone peroneal tendon instability (PTI) surgery Method: The patient going to hospital for sprained ankle was casted for 10 days. Then, the patient applied to the clinic 10 days after his cast was removed. After it was noticed that the patient has peroneal tendon instability on the first day of the treatment, she was transferred to the orthopedics clinic where she was diagnosed with PTI. The patient’s proximal peroneal retinaculum and peroneal tendon were repaired 10 days later. After 2 weeks of a 6-week of immobilization period, the physiotherapy program was initiated. The patient underwent a treatment period for 3 days/week during 4 weeks. Results: Edema and atrophy were evaluated before the treatment. No pain was observed before and after the treatment. Edema and atrophy were determined to decrease, whereas ROM was determined to increase after the treatment. Discussion: In the literature, studies on physical therapy after PTI surgery are rare. The physiotherapy applied after PTI surgery has given successful results.Key Words: Peroneal tendon, Instability, Dislocation, Rehabilitation, Athlete