From January 1, 1971, to December 31, 1985, 425 patients with chronic osteomyelitis of the femur or tibia were seen at the authors' institution. The success rate in this recent experience was 84.4% compared with 50.9% in the authors' results published in 1970. A classification of chronic osteomyelitis is as follows: (1) hematogenous osteomyelitis; (2) osteomyelitis in united fractures (fracture with union); (3) osteomyelitis in nonunion (fracture with nonunion); and (4) postoperative or posttraumatic osteomyelitis in which bone was not fractured. For management of the scarring of surrounding soft tissue, there has been a change to excision of the scarred tissue and reliance on muscle flap, free-tissue transfer, or closure of soft tissues without irrigation with antibiotic solution. In recent years, free microvascular osseous grafts have permitted more aggressive resection of the involved osseous tissue. The predominance of gram-negative organisms and penicillin-resistant Staphylococcus aureus and the occurrence of methicillin-resistant S. aureus continue.