Fifty-five patients with confirmed chronic polyarthritis were admitted to this prospective study. The occipito-cervical region was visualized by plain radiography, computed tomography (CT) and magnetic resonance (MR) imaging. These modalities and the results are compared. In the presence of chronic polyarthritis, radiography of the occipito-cervical region visualized only bone lesions, while CT provided a good picture of both bone lesions and soft-tissue alterations. CT is an effective modality for the diagnosis of chronic polyarthritis in the occipito-cervical region. MR imaging was less sensitive in depicting bone lesions. In comparison with CT, however, MR images produced more frequent and more impressive visualization of soft-tissue alterations. MR imaging is most suitable for visualizing complications of the spinal cord.