Authors have experienced a case of polyostotic fibrous dysplasia and the case is reported in this papey with areview of the literature. A 24 year old male, R.O.K. army private, seen at the 3rd Army Hospital in 1966, withmultiple bony involvment of ribs, pelvis, both femurs, tibias, left fibula, metatarsal bones, right humerus andradius, which revealed characteristic "fibro-cystic appearence" and partial sclerotic changes. The blood chemistryshowed moderately elevated serum alkaline phosphatase and slightly evelvated calcium level. The bone biopsy takenat rib and iliac bone revealed typical appearence of fibrous dysplasia.