One hundred patients (200 hips) under the age 50 years who were scheduled to receive total hip arthroplasty were randomly assigned two different bearing types (one for each hip) to compare cementless THA using alumina-on-alumina ceramic bearing and alumina-on-highly cross-linked polyethylene bearing in terms of clinical and radiographic outcomes. The results of the study indicated that both alumina-on-alumina ceramic and alumina-on-highly cross-linked polyethylene bearings provided significantly improved midterm fixation and pain relief into the second decade after surgery, and provide high rates of survivorship without osteolysis. Alumina-on-highly cross-linked polyethylene bearings were found to produce less squeaking and clicking noises following treatment than the alumina-on-alumina bearing.