Analysis of 221 episodes of hospital-acquired bacteremic urinary tract infection in 4 hospitals of 1 metropolitan area from 1977 to 1981 revealed an over-all mortality rate of 30.8 per cent. The mortality rate attributed specifically to bacteremic urinary tract infection was 12.7 per cent. Of the 28 patients whose deaths were attributed directly to hospital-acquired bacteremic urinary tract infection 19 were on medical services and all had focal or diffuse central nervous system disease, malignancy, alcoholic liver disease or cirrhosis, advanced arteriosclerosis with renal failure and/or diabetes mellitus with obliterative peripheral vascular disease. Extrapolation of these data suggests that 3,520 deaths in the United States each year are directly caused by hospital-acquired bacteremic urinary tract infection but that these deaths may be limited virtually to high risk patients with poor prognoses from underlying diseases.