The results of treatment of eighteen lesions of fibrous dysplasia which of them seventeen lesions were treated with surgery were reviewed at the Department of Orthopedic Surgery, College of Medicine, Hanyang University Hospital. We studied to evaluate the functional clinical results and the recurrence according to the type of disease, grafted bone, methods of treatment and location of lesion. We treated sixteen patients(five males and eleven females) and their mean age was 22.6 years. There was no association with skin pigmentation or dysfunction of endocrine system. Twelve patients had a monostotic pattern and four patients had a polyostotic pattern. Twelve lesions were treated with curettage and bone grafting and four lesions in the proximal femur were treated by internal fixation with curettage and bone grafting. One lesion was treated by en-bloc resection. There were eleven satisfactory results in twelve monostotic lesions and there were four satisfactory results in five polyostotic lesions, but the recurrence were four cases, respectively. The two unsatisfactory results were seen in two patients treated by autografting, but there were three recurrence of four lesions in autografting only, one of five in autografting and allografting, four of eight in allgrafting or xenografting. Four of six lesions in upper extremity were recurred after curettage and bone grafting and five of them showed satisfactory results. In pelvic and lower extremity lesions, the recurrence were occurred in two lesions after curettage and bone grafting and in two lesions after internal fixation and bone grafting. The recurrence does not always provide an unsatisfactory functional results and the recurrence showed higher rate in radiologic pattern of ground glass appearance with-out marginal sclerotic rim, but the recurrence according to grafted bone showed similar rates. Curettage and bone grafting is adequate for a symptomatic lesion and firm internal fixation is needed for a lesion in proximal femur. In use of grafted bone, xenograft or allograft may be preferable to autograft because of the disadvantage of autografting like a increased blood loss, prolonged operation times, etc.