Nineteen patients with rheumatoid C1-C2 subluxation of greater than or equal to 5mm were studied by computerized tomography (CT). CT demonstration of spinal cord compression as defined by loss of posterior subarachnoid space was present in 11/19 (CT+) and absent in 8/19 (CT-). Fourteen patients were examined by a blinded neurologist. Cord compression by CT correlated better with clinical neurologic status than did routine radiographic studies. Absent superficial abdominal reflexes and history of bladder dysfunction correlated highly with cord compression by CT. Two CT+ patients developed neurologic deterioration requiring spinal fusion. Our data suggest that CT is a useful, noninvasive adjunct in management of patients with rheumatoid C1-C2 subluxation.