The incidence of cervical myelopathy and subluxation was investigated in 48 patients with rheumatoid disease who had three or more major lower limb joint replacements. Eight (17%) developed cervical myelopathy requiring cervical fusion. This was the subsequent cause of death in two. Four further patients demonstrated clinical features of myelopathy. Cervical subluxation was present in 29 of 44 (66%) in whom adequate radiographs were available. The development of cervical symptoms and signs could not have been predicted from the sex, age of onset, duration of disease or steroid therapy. Radiographic changes in the cervical spine were independent of major lower limb joint destruction and were often not present when planning a programme of joint replacement. Fifty-one control patients were studied. Cervical myelopathy occurred in 2 (4%) and subluxation in 24 (47%). The development of rheumatoid changes in the cervical spine was unrelated to involvement of the hip or knee joints in the control group. There was a significant (p less than 0.05) increase in the incidence of cervical myelopathy in patients with multiple lower limb joint replacements compared with the control population.