Antibiotic-acrylic bone cement composites demonstrated antibacterial activity as a result of diffusion of antibiotic from bone cement into surrounding enviroment, accordingly, the use of antibiotic incorporation to bone cement for the prevention and treatment of infection after joint surgery replacement has been adovocated. Early report of clinical success by using antibiotic-acrylic bone cement composites are encouraging. Our authors applied this concept to the treatment of chronic osteomyelitis. Antibiotic contained with bone cement was chosen by sensitivity test on pus culture finding. Seven cases of chronic osteomyelitia treated by using antibiotic-acrylic bone eement composites were .studied in the Department of Orthopaedic Surgery, Kyung Hee University Hospital from July 1979 to March 1981. The follow-up period was from 3 months tc 22 months. The results were as follow: 1. Six cases showed no evidence of recurrence except one by using antibiotic acrylic bone cement composites. 2. The impregantion of antibiotic in acrylic bone cement shall be regarded to be effective in increasing the local antibacterial activity by leaching the antibiotic into surrounding tissue over a period continiously in treatment of chronic osteomyelitis. 3. The use of antibiotic-acrylic bone cement compositea into dead space by saucerization are consid- ered an one such approach to the decrease of dead space. 4. The impregnation of antibiotic in acrylic bone cement is regarded a new concept in treatment of chronic osteomyelitis.