Twenty two patients aged 18 to 47 years were treated for 24 infected bone defects and nonunions (6 femora and 16 tibiae) by radical resection of the necrotic bone and distraction osteogenesis techniques to regenerate the excised bone. Nonunion, infection, limb shortening, deformity, and osteoporosis were all addressed simultaneously. All patients underwent either bifocal or trifocal internal lengthening by bone transport technique of sliding a bone fragment, producing distraction osteogenesis behind it until the defect was bridged. The mean bone defect was 8.2 cm, with a range up to 16 cm. Eradication of the infection was achieved in all cases prior to the removal of the fixator. Problems with union requiring bone graft augmentation were encountered in three patients. One patient, who sustained a refracture, underwent an amputation. The mean time to union was 4.4 months, if the time was taken from the day the intercalary segment came in contact with the targed segment. Deformity and length inequality were corrected successfully in the majority of the patients. The bone result was excellent in 15 cases, good in 7, fair in one, and poor in one. The functional result was excellent in 11 cases, good in 8, fair in 3, and poor in 2. Distraction osteogenesis treatment seems to be superior to any other method used for treatment of infected bone defects and nonunions, especially in terms of eradication of osteomyelitis and quality of bone union. However, the ability to achieve excellent bone result in even the worst infected bone defects and nonunions does not guarantee a favourable functional result, unless the patient has an acceptable neurovascular status.