Objective To evaluate the mid-and long-term clinic results of ceramic-on-ceramic joint in total hip arthroplasty (THA) in younger patients.Methods A retrospective review was made on 72 younger patients who had THA with ceramic-on-ceramic bearings due to femoral head necrosis or inborn hip dysplasia between March 2001 and March 2011.There were 32 females and 40 males,at a mean age of (35.2 ± 7.6)years (range,17-45 years).Patients were evaluated with Harris hip score and University of California,Los Angeles (UCLA) activity score.Radiological findings were recorded including component loosening,ostelysis,and ceramic bearing related complications.Results Duration of followup was (8.5 ±2.4) years (range,5-12 months).At the final follow-up,Harris hip score was increased to (93.8 ±4.3)points (range,85-100 points) compared to preoperative (46.1 ± 12.3) points (range,27-70 points) and UCLA activity score was increased to (7.1 ± 1.4)points (range,4-10 points) compared to preoperative (4.0 ± 1.2) points (range,2-6 points) (P ＜ 0.05).At the final follow-up,no osteolysis or prosthesis loosening occurred,but there were ceramic sandwich liner fractures in two patients (two hips),dislocation in one patient (one hip) and squeaking in one patient (one hip).After revision due to the ceramics break,the 8-year survival rate was 97％ (95％ CI91.9-100.0).Conclusion Ceramicon-ceramic joint in THA satisfies the activity demand in younger patients,with excellent mid-and longterm clinical results.