In ceramic-on-ceramic total hip arthroplasty (THA), modular acetabular component with a sandwich insertion was developed and evaluated mid-term clinical results. 35 hips had undergone cementless ceramic-on-ceramic THA with sandwich cup (Kyocera, Kyoto, Japan). The mean duration of follow-up was 5 years. 6 hips had undergone component revisions. The reasons for revision included infection in 1 hip, dislocation with loosening in 2 hips, alumina liner fractures in 2 hips, and cup dissociation in 1 hip. All femoral and acetabular components showed no loosening in the unrevised hips at the time of the last follow-up. None of the 29 unrevised hips had osteolysis.