The practice of holding combined orthopaedic and rheumatology clinics is widespread, but no attempt has been made to assess their usefulness. In a one year prospective study patients were randomised either to a combined clinic with a rheumatologist and an orthopaedic surgeon or to a clinic with an orthopaedic surgeon alone. The details of the patients' disease, the interview, the surgeons' and rheumatologists' responses, and the patients' opinions were recorded on questionnaires. Interviews were appreciably longer in the combined clinic, and more referrals for surgery were made. The rheumatologist correctly predicted the need for surgery in 95% of cases, and his presence in the clinic was considered desirable by the surgeon, principally when the referral letter was inadequate. It is concluded that most patients with rheumatic diseases can be seen more efficiently in routine orthopaedic clinics provided a good quality letter of referral is sent.