We retrospectively reviewed 474 patients (492 hips) with a contemporary cemented total hip arthroplasty (THA) (mean age, 38.9 years) and 504 patients (532 hips) with a cementless THA (mean age, 39.3 years). Patients were evaluated clinically and radiographically. The mean follow-up was similar (14.5 vs 14.8 years) in both groups. The mean postoperative Harris hip scores (93.6 vs 94.7 points), the mean Western Ontario and McMaster Universities Osteoarthritis Index scores (12 vs 13 points), and the mean University of California, Los Angeles activity scores (6.9 vs 7.1 points) were similar between the 2 groups. Incidence of acetabular osteolysis (16% vs 20%) and femoral osteolysis (8% vs 9%) was similar between the 2 groups. Survivorship of cup (86% vs 82%) and stem (98% vs 98.5%) was similar between the 2 groups. Periacetabular osteolysis constitutes the major challenge in modern THAs in young patients.