PURPOSE: To assess the characteristic features of MR findings which would be useful for the differentiation of various spinal diseases involving paraspinal soft tissue mass. MATERIALS AND METHODS: We retrospectively reviewed MR findings in 31 cases(M:F=20:11) of spinal disease in which paraspinal mass was involved. The breakdown of cases was as follows : spinal tuberculosis, 12; spinal metastasis, 13; multiple myeloma, 3; pyogenic spondylitis, 2; spinal aspergillosis; 1. RESULTS: The pattern of bone marrow invasion in spinal metastasis, multiple myeloma, spinal tuberculosis and aspergillosis was mixed ; focal, homogeneously diffuse and inhomogeneously patterns were seen. Pyogenic spondylitis showed inhomogeneously diffuse invasion; an intravertebral abscess was seen in the only five cases of spinal tuberculosis. Vertebral posterior compartment invasion was observed in seven cases of spinal tuberculosis, two of multiple myeloma, the one case of spinal aspergillosis and in all 13 cases of spinal metastasis. This and multiple myeloma showed no disc space invasion, in any case, but all cases of infectious spondylitis showed such invasion. Peripheral rim-enhancement in the paravertebral mass was seen in 11 cases of spinal tuberculosis, one case of pyogenic spondylitis and the case of aspergillosis. Bilobate anterior epidural mass was noted in 60% of spinal tuberculosis cases, 36% of spinal metastasis and one case of pyogenic spondylitis. CONCLUSION: MR findings of spinal disease involving a paraspinal soft tissue mass were useful for differentiation.