External skeletal fixation is used widely in the management of open or closed tibial fractures, but delayed healing is common. There is concern that this might be due not only due to the severity of injury but also to the mechanical conditions imposed at the fracture site by the fixator. Since fractures treated by external skeletal fixation can rarely be reduced to perception nor held with absolute stability, union occurs by indirect healing, which is acutely sensitive to both the charactericstics and timing of mechanical stimulation. So, the achivevment of the optimum mechanical environment is particularly important where delay in bone healing is likely. Ilizarov external fixator is useful in treating open fractures of the tibial shaft because it permits axial micromotion which enhances bridging callus formation with stable fixation as well as its complications such as infected nonunion or limb length discrepancy. The impared healing with external fixation is often caused by wrong surgical technique, such as distraction of fracture fragments by fixation device. Sequential compression at fracture site may overcome any fracture gap in external skeletal fixation and also enhance endosteal bone formation. We applied sequential compression forces at the fracture site in 18 open fractures of the tibial shaft, trated by Ilizarov external fixator with or without autogenous bone grafting. Sequential compression technique is composed of initial compression with 1 mm/wk for 4 weeks and then compression 1 mm/10 days until adequate apposition of cortex and callus formation in radiograph. We acquired successful bony union in all cases except one which had additional bone grafting in open fractures of the tibial shaft by sequential compression technique using Ilizarov device.