Four hundred ninety-nine nosocomial infections (with 657 isolates) in 288 Surgical Service patients were monitored from February 1986 to June 1987 (17 months) to determine the influence that pathogen or site of infection had on the length of hospital stay. Patients with upper respiratory and skin infections were more likely to have significantly longer length of stay than those with infections in other sites. Infections with Haemophilus influenzae and Pseudomonas aeruginosa were more likely to yield longer culture to discharge periods than other organisms in certain settings. Extended lengths of stay were common in patients with nosocomial infections.