A study of open joint injuries treated at the Los Angeles County-University of Southern California Medical Center from July 1969 through July 1973 showed that the vast majority of these injuries were at the knee. Three types of injury were identified: those associated with fractures, injuries without fracture, and gunshot wounds. All patients were treated with antibiotics, surgical débridement and irrigation, and installation of polyethylene tubes into the joint as a system of postoperative closed irrigation. The over-all infection rate was 2.1 per cent. The results of treatment indicate that the irrigation system can be a source of contamination. Our recommended treatment for open wounds in joints is wide-spectrum systemic antibiotics, surgical débridement, irrigation of the joint and soft tissues, and primary closure. Prolonged suction-irrigation treatment postoperatively should only be done for specific indications: excessive contamination or excessive tissue damage when the wound to the joint should be closed primarily.