Thirty-eight patients were given 350μc to 750μc of sodium fluoride F 18. The nuclide was administered both orally and parenterally. Photoscans were performed in 35 cases, and point counts only were done in the other three. Diagnostic scans were found at all dosage levels given. Normal scans were found in cases of osteochondroma, soft-tissue sarcomas, rheumatoid spondylitis, Engelmann's disease, and aseptic necrosis of femoral heads. Abnormal scans were found in 25 cases including four cases of metastatic bone tumors in which roentgenograms were either normal or equivocal. The radionuclide has been found to be well tolerated. The radiation hazard with sodium fluoride F 18 is minimal, and serial scans have been performed successfully in several patients.