The new osteomyelitis classification was worked out on the strength of treatment results of 361 patients. Four types of long bones lesions are marked out: medullar, superficial, focal and diffuse. The kind of surgical treatment is determined according to the lesion type. Authors worked out a modification of osteoplastic trepanation--a "grip-sack" technique, which is used for medullar and focal femoral and tibial osteomyelitis. Long term follow-up results are obtained in 271 (77,7%) cases. The developed classification eases the standardization of follow-up results and permits treatment planning.