Computer usage in hospital epidemiology has grown rapidly in recent years. In fact, among the departments concerned with measuring and improving quality, infection control leads the way in applying microcomputers to its information management needs. An obvious use of computers is to help manage surveillance databases. Other compelling reasons to collect and analyze data using computers include 1) newer methods to detect outbreaks; 2) classifying patient risks using indices specific to each type of infection; 3) decision analysis as a method of addressing cost-benefit questions; and 4) the future potential of expert computer systems.