Nonenhanced magnetic resonance (MR) images and arthrotomograms of temporomandibular joints (TMJs) were compared in 18 patients with rheumatic disease. Of 22 symptomatic TMJs, arthrotomography was unsuccessful in three (14%). MR imaging showed extensive rheumatic abnormalities in two of these three joints and internal derangement in one. In another three joints (14%), both imaging modalities showed normal findings or internal derangement. In the remaining 16 joints (72%), arthrotomographic findings were interpreted as rheumatic, whereas MR findings were interpreted as rheumatic in 14 joints and as internal derangement in two. Surgical correlation in 11 joints indicated superiority of MR imaging for assessment of moderate and severe rheumatic TMJ involvement. MR imaging seemed to be of limited value in early diagnosis due to its inability to show synovial proliferation. Indirect signs of synovial proliferation could be shown with arthrotomography, which may be helpful in early diagnosis of rheumatic TMJ disease.