Objectives: The objective of this study was to assess the donor site morbidity in patients having anterior cruciate ligament reconstruction (ACLR) using peroneus longus tendon (PLT) autograft. Methods: A prospective cohort study was conducted at the orthopedic department of Pakistan Atomic Energy Commission General Hospital, Islamabad, from July 2021 to July 2023. A total of 150 patients aged between 20 and 40 years with an anterior cruciate ligament injury requiring ligament reconstruction were included in the study. Exclusion criteria included previous ankle ligamentous injuries, fractures or surgeries around the ankle, and high-risk sports like football. After the ACLR surgery, the patients were assessed for pain, range of motion (ROM), and muscle power in the 6th week, 3rd month, and 6th month. Return to jogging without discomfort at the ankle during 1st min of jogging was assessed at six months. Results: Of the 150 patients, 142 (94.6%) were male and 8 (5.4%) were female. The mean age of participants was 32.53 ± 4.78 years. Pain and loss of ROM around the ankle were reduced after six months compared to three months and six weeks, that is, P < 0.05. Muscle power was increased after six months (n = 152; 94.0%) (P < 0.001). In the 6th month, 133 patients (88.7%) were able to jog without discomfort around the ankle joint during the 1st min of jogging, but 17 patients (11.3%) started jogging after six months without discomfort at the ankle joint during the 1st min of jogging (P < 0.001). Conclusion: ACLR using the PLT autograft resulted in a good functional outcome, smooth rehabilitation with an early return to sports, and minimal complications at the donor site.