In an investigation on 2126 operative patients in a hospital in 1992, 227 were found to have nosocomial infection with 241 person-times. The nosocomial infection rate was 10.68% and the case infection rate was 11.34%. They were higher than nonoperative nosocomial infection rate and case infection rates were 4.85% and 4.98%, respectively. The main sites of infection were postoperative cuts, in lower respiratory tract and urinary tract. These three parts held 82.12% of the sites of infection.