One aspect of the Certification Board of Infection Control's (CBIC) task analysis survey was to determine those tasks done most frequently and considered most important by ICPs. A randomized stratified sample of ICPs was taken from U.S. hospitals of various bed-size categories. There were 473 responses (78.8%) from a targeted sample of 600 ICPs. Statistical analyses were done to find if a relationship existed between hospital size and the tasks performed. The frequency of performance and importance of the majority of infection control tasks studied were found to vary in relation to hospital size. Some tasks were found to be both important and frequently performed by the majority of ICPs in all hospital bed-size categories. These included performing and reporting epidemiologic surveillance, educating personnel, developing infection control policies and procedures, and consulting with hospital personnel. Other tasks were found to be relatively less important and infrequently performed by the majority of ICPs in all hospital bed-size categories. These included performing bedside patient care procedures, recommending specific antimicrobial therapy, and using statistical methods. The greatest differences in the performance of tasks were found in the subsample of the ICPs from hospitals with less than or equal to 100 beds.