This prospective, randomized, multicenter study of alumina ceramic-on-alumina ceramic bearing couples includes 452 patients (475 hips). Their average age was 53 years with approximately two thirds men and 82% with osteoarthritis. At an average 8-year follow-up, clinical results were excellent and cortical erosions significantly less than in the conventional polyethylene-on-metal bearing group. Nine hips have undergone revision of one or both components for any reason. Of the 380 ceramic liners, 2 (0.5%) have fractured requiring reoperation, and 3 (0.8%) ceramic patients reported a transient squeaking sound, one of which had a head and liner change due to groin pain secondary to psoas tendinitis at 5 years. With no revisions for aseptic loosening and minimal cortical erosions, alumina-ceramic bearing couples are performing in a manner superior to the polyethylene-on-metal bearing in this young, active patient population.