Treatment of bone defects caused by infection is very difficult. If no filler is used, a dead space is created and this is a disadvantage for the healing of infection. However, filling the infected bone defect with free autogenous iliac bone graft also slows the healing of infection and bone absorption often occurs. We filled infected bone defects of 10 patients (6 men and 4 women; mean age: 48.1 years) with hydroxyapatite tricalcium phosphate (HAP-TCP) from 1992 to 1997. In all patients, methicillin-resistant Staphylococcus aureus was isolated from the infected focus. Administration of appropriate antibiotics and extended resection of the infected focus were performed, and the bone defect was packed with HAP-TCP after control of the infection. Wound healing, recurrence of infection, bone union, and HAP-TCP bonding were investigated. Wound healing was obtained in all patients and recurrence of infection did not occur. Bone union and HAP-TCP bonding were also obtained in all patients, and absorption of HAP-TCP did not occur. It is important for the treatment of infected bone defects that appropriate antibiotics are administered, the infected focus is excised completely, and the bone defect is filled adequately. When the former 2 conditions were fulfilled, HAP-TCP was not absorbed and was an effective filler for bone defects.