We surveyed general and family practitioners to evaluate their patterns of referring musculoskeletal disease patients to rheumatologists and orthopedists. Patients who had rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis were most often referred to rheumatologists, whereas patients with osteoarthritis, persistent low back pain, and post-traumatic knee pain were most often referred to orthopedists. As conditions worsened in severity, referrals were more frequent. Patients with conditions that were difficult to diagnose, such as possible shoulder tendinitis that was unresponsive to initial nonsteroidal therapy, undiagnosed polyarthritis, and intermittent knee swelling with pain, were most often treated without referral and, when referred, were most often sent to orthopedists. Belief in the effectiveness of rheumatologists or orthopedists correlated strongly with reported referral behavior, yet most respondents considered themselves capable of managing the majority of patients with musculoskeletal diseases. Neither practice arrangement, board certification, nor educational background affected referral behavior. However, younger physicians were more likely (P = 0.002) to refer patients to rheumatologists. Multivariate analysis showed that the significant predictors of global referral behavior were belief in the effectiveness of subspecialists and a small number of musculoskeletal problems seen by the generalist. The predictors of referral to rheumatologists were belief in rheumatologist efficacy and young physician age.