OBJECTIVE AND IMPORTANCE: Cervical arthroplasty is a relatively new method to maintain motion after cervical anterior discectomy. Two cases are presented in which bony fusion occurred around a cervical disc prosthesis. CLINICAL PRESENTATION: A 30-year-old man and a 49-year-old woman underwent a right-sided anterior cervical discectomy because of pain in the right arm resulting from a herniated disc (C5-C6). INTERVENTION: A cervical disc prosthesis (Bryan disc prosthesis) was implanted. Postoperatively, the patients were completely free of pain. At the regular 1- and 2-year follow-up examinations, bony fusion was seen on plain x-rays of the cervical spine. The patients were still completely free of signs and symptoms. CONCLUSION: This is the first report in the literature of bony fusion after cervical arthroplasty with the Bryan disc prosthesis.