Background: Common knee injuries pertaining to the anterior cruciate ligament (ACL) have traditionally been treated with a variety of graft repair techniques involving groups of grafts for bone, patellar tendon, and hamstrings. Objective: The aim of the current study was to assess the donor site and functional outcome morbidity of single bundle ACL Peroneus tendon grafting for reconstruction. Patients and methods: At the Orthopedic Department of Zagazig University Hospitals, a prospective cohort study was carried out, on 18 patients with ACL tear during the period from January 2022 to July 2022. Arthroscopic Peroneus longus tendon autograft was used for anatomic single bundle ACL repair on all patients. Results: IKDC score considerably increased from 45.83 (SD 7.46) to 78.12 (SD 6.04); 15 (83.3%) patients had excellent score and 3 (16.7%) patients had good score in AOFAS. complications 13 (72.2%) cases were non-complicated and 27.8% were complicated (hemarthrosis 5.6%, loss of terminal flexion 5.6%, pain 5.6%, superficial infection 5.6% and Transient apraxia sural nerve 5.6%). Conclusion: Peroneus longus tendon is effective and secure autograft for arthroscopic anterior cruciate ligament reconstruction; restoration of knee function is adequate, with few donor site morbidities.