Background: Osteochondral autograft transfer (OAT) is very helpful in managing osteochondral defects of knee joint. Objective: Evaluation of the radiological and functional results of osteochondral autograft in treatment of osteochondral defects. Patients and Methods: Eighteen patients with chondral and osteochondral lesions in the knee joint treated by Osteochondral Autograft Transport System (OATS) were included. Patients were recruited from Zagazig University Hospital outpatient clinic and followed up for more than six months. Results: The best results were generally encountered in small lesions, chondral and osteochondral defects, that had normal articular cartilage surrounding the lesion, and the average final subjective chondral defect score at the end of the follow up was with (50.1 ± 6.4) in comparison to the average preoperative subjective score was (27.4 ± 6.9). There was a statistically significant difference between the mean of the preoperative and the final postoperative subjective chondral defect scores, indicating marked postoperative subjective improvement. Also, highly statistical significantincreasing in postoperative Lysholm Score (88.3 ± 8.7) when compared with preoperative one (46.5 ± 15.2). Conclusion: OATS were proved to be a useful procedure in treatment of osteochondral defect of the knee joint as it produced a high good to excellent outcome in our series patients with minor complications.