Available data on the characteristics of infections in different types of ICUs are limited. Between May and July 1984, overall infections rates of patients in the ICUs and in the general wards at the Detroit Receiving Hospital were 19.2% and 9.8%, respectively (p< .001). Specific infection rates (number of infections/100 admissions in each unit) were 35.2% for surgical unit, 29.8% for burn unit, 13.9% for medical unit, and 6.6% for coronary unit. Of the total number of patients admitted, only 1.9% patients in the coronary unit became infected while 10.9% to 13.6% in the other three units acquired infection. There were more infections per patient in the surgical unit than in the others.Device-related infections involving the urinary and respiratory tracts were the most common. Predominant pathogens isolated in order of frequency wereEsche-richia coli, Pseudomonas aeruginosa, Klebsiella pneu-moniae, andStaphylococcus aureus.Death rates among the infected patients were high; of those infected, nine patients (75%) of 12 in the surgical unit and ten (91%) of 11 in the medical unit died. For those who died, the duration from ICU admission to infection was 2 to 22 days (mean 6.5) and length of survival after becoming infected was 2 to 50 days (mean 22). The mortality rates between the infected and uninfected patients in the medical, surgical, and burn units were significantly different (p< .0005). Awareness of patterns for nosocomial infection in different ICUs is of, value in the adoption of appropriate infection control policies within each unit.