From March 1987 to June 1991, 111 open comminuted fractures of long bone were treated with the Orthofix and Ilizarov external fixator. The cases were followed up for a minimum of 12 months upto 54 months with an average of 31.4 months. The clinical results were as follow: l. Among 111 cases, 82 were tibia fractures, 23 were femur fractures, 6 were humerus fractures. 2. 46 cases of tibia fractures and 18 cases of femur fractures were treated with Orthofix fixator. 36 cases of tibia fractures, 5 cases of femur fractures, and 6 cases of humerus fractures were treated with Ilizarov fixator. 3. 66 cases had initial bone defects which ranged from 2 cm to 17cm, averaging 2.7cm. The bone defects were treated with cancellous bone graft (52 cases), fibular graft (4 cases), vascularized fibular graft (2 cases), and internal lengthening (8 cases). The two cases of large bone defect (14cm and 17cm) were treated by internal lengthening (trifocal) after two level corticotomy with Ilizarov fixator. 43 soft tissue defects were treated with secondary closure, split thickness skin graft, and musculocutaneous flap. The complications developed were as follows; nonunion in 6 cases, osteomyelitis in 4 cases, severe pin tract infection in 4 cases, remaining limb length discrepancy more than 1cm in 13 cases, and adjacent joint contracture in 54 cases. The nonunion, osteomyelitis, and limb length discrepancy were treated by a combination of bone transport and limb length discrepancy were treated by a combination of bone transport and limb lengthening (trifocal internal and external lengthening). Average union period were 34.4 weeks in tibia fractures, 28.4 weeks in femur fractures, and 16.2 weeks in humerus fractures. The functional results of tibia fractures according to Karlstrom and Olerud were as follows; excellent in 16 cases, good in 32 cases, acceptable in 24 cases, and poor in 10 cases. We recommend that Ilizarov external fixator is very useful initial treatment method in severe open comminuted fractures because it could reduce associated complications such as remaining limb length discrepancy and nonunion.