Three-phase radionuclide bone scan consisting of a radionuclide angiogram an immediate postinjection blood pool image and 4hr delayed images was randomly performed in 182 patients who had been suffered from either local pain or tenderness. Authors analysed 3 phase bone scan in 74 patients with correct diagnosis proven surgically or clinically from July 1987 to August 1988. The results were as follows; 1. Overall sensitivity of 3 phase bone scan was 85.4% sensitivity in patients with an osseous lesion was 90.4% as opposed to 72.7% in patients with a nonosseous lesion. 2. There was no difference in the detection rate of the osseous lesions between the 3 phase bone scan and the delayed image bone scan. However because the detection rate was higher on the 3 phase bone scan than it was on only the delayed image bone scan(55%) instances of the nonosseous lesion we would suggest that 3 phase bone scan might be obtained in cases suspected of the non-osseous lesions. 3. When the presumptive diagnosis was a bone tumor sensitivity and specificity for malignan-cy were 67% 100% respectively. 4. In differentiating osteomyelitis from cellulitis sensitivity was 94% specificity was 100%. 5. 3 phase bone scan was able to provide the precise information about either vasculaturity or localization of lesion in some cases of soft tissue mass and avascular necrosis of hips.