Introduction.Removal of a large fragment of avascular bone in open fracture case is still controversial. Replacement procedure using autogenous bone graft has its limit in volume and the use of synthetic bone graft is still expensive. Materials and methods. We conducted an experimental study using white rats Winstar strain. Their femurs were fractured segmentally and stripped from surrounding soft tissue. The bone fragments were then contaminated with Staphylococcus aureus and Bacillus subtulis. The contaminated fragments received microwave irradiation in different time periode using domestic microwave oven.Results.Microorganism from contaminated bone fragments failed to grow after 7 minutes or more exposure to microwave irradiation.Conclusions.Sterilization of a large fragment of avascular bone contaminated with Staphylococcus aureus and Bacillus subtulis can be achieved using microwave irradiation in domestic microwave oven for certain time period. This method of sterilization of bone fragment is cheap, easily used, and an effective way to process contaminated bone.