Authors experienced a case of polyostotic fibrous dysplasia which confirmed by clinical and radiographical examinations at Busan National University Hospital, and reported it with review of the literature. The patient was 20 years old male, who had the pain of both arms and clavicles since his childhood insidiously. His family history was not contributory. Roentgenograms of bones revealed a characteristic fibro-cystic appearance with partial sclerotic changes in the calvarium, ribs, clavicles, femurs, humeri. The blood chemistry showed no remarkable abnormal findings, and other laboratory values as well.