Authors retrospectively compared the 99mTc MDP bone scans and corresponding MR imagings in 20 patients with histologically proven malignancy. Mean interval of the two studies was 16.6 days. Cancer diagnosis included 8 lung, 2 each of colon, breast, stomach, 1 each of prostate, thyroid, malignant lymphoma and 3 adenocarcinoma of unknown primary site. Of the 105 regions compared, 46 regions were positive for metast,ases in bone scans ar MR imagings. 30 regions(65.2%) were positive by bone scan and 44 regions(95. 7%) by MR imaging. 87 regions(82.9%) were concordantly positive or negative by bone scan and MR imaging, but 18 regions(17.1%) were discordant. In the discordant regions, 16 regions positive in MR imaging were negative in bone scan. The greatest number of discordant findings occurred in the cervica.l region and in the patient with stomach cancer. Our results suggest t.hat the sensitivity of MR imaging is great,er than that, of bone scan in det.ecting spinal metastases. And bone scan is useful screening test of metastasis for evaluting entire skeleton including spine.