Joint consultation sessions between general practitioners (GPs) and specialists to examine patients for whom decisions about referral are difficult are thought to be helpful, but their effects have not been evaluated. In a randomised, controlled trial we studied the effects of joint sessions of GPs and orthopaedic surgeons on referral and intervention rates. During 1.5 years, 12 GPs (in groups of three) held monthly joint consultation sessions with four participating orthopaedic surgeons: patients were seen by one orthopaedic surgeon in the presence of three GPs. Patients were included in the trial if the GP was uncertain about the diagnostic or therapeutic management and if referral was considered; and excluded if referral was urgently necessary or if there was some other clear indication for referral. By a randomised consent design, patients were assigned to joint consultation sessions (n = 144) or a usual-care control group (n = 128). A year later the patients were examined by an independent orthopaedic surgeon. There were significantly fewer referrals (51/144 [35%] vs 87/128 [68%], p < 0.01) and diagnostic actions in the intervention group than in the control group, without negative effects on health or functional status. More patients in the intervention group were symptom-free at 1 year (35% vs 24%, p < 0.05). Joint consultation sessions of GPs and orthopaedic surgeons within the framework of general practice resulted in more efficient care, with better targeted examination, treatment, and referrals.