Tibial segmetnal fracture, usually caused by strong external force has recently been increased in frequency because of increased traffic accident. This type of fracture has been well known to be very difficult to manage on reduction and maintenance of reduction, and also that it has high rate of complications such as delayed union, nonunion, infection and etc., because of high incidence of open fracture and association with other injury. For the management of this type fracture there are various methods from conservative care to operative treatment such as internal or external fixation. We analyzed nonunion of 8 cases who underwent interlocking intramedullary nailing for tibia segmental fracture. The results were as follows ; 1. Interlocking intramedullary nailing for the treatment of tibia segmental fractures were done in 29 cases(76.31%) out of total 38 tibia segmental fractures. 2. Nonunion occurred in 8 out of 29 cases(27.6%). 3. Nonunion occurred at the distal fracture site in 7 cases and both proximal and distal fracture site in 1 case. 4. Nonunion occurred in 4 cases of open fractures, 3 cases of closed fractures with compartment syndrome. 5. Nonunion occurred in 5 cases of Melis type IV, fracture, 2 cases of type I and 1 case of type II fracture. Although the interlocking intramedullary nailing is thought to be good method for the tibia segmental fracture, our study showed relatively high rate of nonunion especially, at the distal fracture site, in case of open fracture, associated with compartment syndrome and Melis Type IV fracture. On the basis of this study we recommend that closer attention should be paid to the method of treatment, fracture type, severity of comminution, open or closed fracture, degree of soft tissue injury, and fracture site.