Five patients with multiple myeloma were studied by serial radioactive strontium 87mSr citrate or carbonate bone scans over a period of one year. Severe and constant pain was associated with abnormalities on the scans; subsequent roentgenograms of these areas invariably showed vertebral collapse or infraction. On the other hand, old vertebral collapse, per se, did not give rise to bone pain. It is concluded that the cause of the bone pain in myeloma is infraction. Local treatment of such bones with radiation may prevent vertebral collapse and pathologic fracture.