Bone scintigraphy with sup(99m)Tc-MDP was performed on a case with a Ollier's disease. Compared with Bone X-ray examinations, increased activity is noted in the ribs, hands (esp. left), left humerus, left tibia and left foot. Tumor scintigraphy with /sup 67/Ga-citrate shows slightly increased accumulation in comparison with sup(99m)Tc-MDP findings. However, apparent change was not noted compared with the previous scans. So, malignant change was negative. Malignant bone tumors usually show high activity, but some benign tumors also show high uptake. So, a differential diagnosis of bone disease using sup(99m)Tc-phosphorous compounds is occasionally difficult. In case of Ollier's disease, a follow-up bone scintigraphy is useful for evaluation of tumor growth, because malignant changes were accompanied by intensive uptake of sup(99m)Tc-MDP. Also, /sup 67/Ga-study is necessary for the differentiation of bone disease.