Nosocomial infection mortality is an important problem, with estimates of magnitude placing it among the 10 leading causes of death in the United States. This is a preliminary study to determine the potential usefulness of death certificate data in providing information about the frequency of nosocomial infections and their association with other conditions listed as underlying or contributing causes of death. Multiple cause-of-death data were examined for 1988, to identify the number and characteristics of persons dying with nosocomial infections. The mortality rate associated with nosocomial infections found on death certificates was 3.83 per 100,000 person-years. This method needs to be validated by further work. Because nosocomial infections are a contributing rather than an underlying cause of death, multiple-cause mortality data may provide another way to estimate the magnitude of this problem.