Background: The purpose of hip arthroplasty is to restore function by restoring normal anatomy and thus normal hip biomechanics. The aim of the present study was to evaluate the clinical and radiologic outcomes of young patients with degenerative osteoartheritis who have a total hip arthroplasty (THA). Patients and methods: This retrospective study wasconducted in Orthopedic Surgery Department, Faculty of Medicine, Zagazig University on 18 patients with degenerative osteoarthritis. Patients with significant disabling hip pain and moderate to severe functional limitation of activities of daily living due to osteoarthritis of the hip joint with any of the etiologies. Clinical assessment was done byusing Harris Hip Score at 6 weeks, 3 and 6 months follow up, also we used radiographs in analyzed with reference to signs of loosening at end of 3 months and 6 month. Results: Mean of pain score improved from marked pain (10.1±8.26) to slight pain (38.7±5.04) post- operative. Mean Walk score improved from (1.1±1.02) pre-operative to (9.3±1.53). Post- operative. Mean of Support score improved from (1.9±1.1) pre-operative to post- operative (7.8±2.39). Limping improved from moderate limping (2.2±2.6) pre-operative to (9±1.45) postoperative. Mean climbing upstairs score in most cases improved from (0.55±0.51) pre-operative to (1.9±0.32) post- operative. A statistically significant increase in points of all parameters postoperative. Wear Shoes stocks score improved from (2±0) to (3.1±1.02) post- operative, sitting improved from (1.6±1.53) to sit comfortably to any chair for one hours (4.3±0.97) postoperative. Mean of uses public transportation increased to be postoperative 0.78±0.43 and deformity improved to be 3.1±0.58.Range motion improved to do normal motion range post- operative. Conclusion: Cementless total hip arthroplasty has reassuring results in patients <50 years of age. It is not associated with any significant early or late complications and has outstanding functional outcomes. Patients usually do not experience any pain, limping, difficulty in walking and attain normal limb length. They develop no restriction in the range of movement.