As the saftest and simplest method of immobilization treatment, external fixation is indicated in IIIb open tibial shaft fractures with extensive damage to soft tissue and bone. This enables better wound treatment, patient transport and performace of surgical treatment such as plastic and reconstructive surgery, orthopedic surgery. From the march 1994 to september 1997 14 cases of IIIb open tibial shaft fractures were treated with clamp external fixator either Orthofix or DynaExtor. The purpose of this study is to determine indication of clamp external fixator and investigate its outcome as well as complications and solutions. 11 males and 3 females were followed for 29.3 months on an average. Fractures mainly occurred at mid 1/3 of tibial shaft and its pattern was most frequently comminuted one. Mean bony union time was 46 months. There were 1 case(7%) of delayed union, 2 cases(14%) of nonunion, 6 cases(42%) of reduction loss, 4 cases(28%) of deep infection including 2 cases(14%) of osteomyelitis, 6 cases(42%) of pin tract infection, 2 cases(14%) of malunion and 3 cases(21%) of ankle stiffness. Conclusively for the creation of a suitable environment of fracture healing and prevention of complications such as delayed union, nonunion and deep infection, thorough debridement and irrigation followed by adequate stabilization of bone, early soft tissue coverage and early prophylactic bone graft is paramount important in the treatment of IIIb open tibial shaft fracture since it is high energy trauma. In addition, initial firm fixation for the prevention of reduction loss and active and passive exercise for the prevention of ankle stiffness and pin tract infection or loosening should be taken into careful consideration.