Simple bone cysts are encountered in the pediatric age group and often present as a minor pathologic fracture through a lytic lesion in a long bone close to the growth plate. The author has been studied 9 cases of solitary bone cyst with pathologic fracture which were histologically proven in the Department of Orthopaedic Surgery, College of Medicine, Pusan National University dating from Aug. 1983 to July 1990. Solitary bone cyst with pathologic fracture was treated by plaster immobilization to stabilize the fracture site and theresfter local steroid injection and/or currettage and bone graft in the remaining cyst. The mena folow up period was 36months and the results were as follows:1. Pathologic fractures were united by plaster immobilization in all 9 cases. The mean union time was 7.8 weeks. 2. The fractures were healed with partial obliteration of the simple bone cyst. 3. The remaining cysts which were left after union of the pathologic fracture were treated by local steroid injection and/or currettage and bone graft. The mean healing time was 28 months. 4. Plaster immobilization to stabilize the fracture site and thereafter local steroid injection and/or currettage and bone graft of the remaining cyst were recommended in the treatment of simple bone cyst with pathologic fracture.