An increasing proportion of the U.S. population resides in nursing homes (NHs). No surveillance system exists for infections in these facilities. To determine the incidence and types of infections in NH residents, and to identify predictors of death among residents with infections, we initiated a surveillance system at 13 NHs in California during a 6-month period from October 1989 through March 1990. The study included 1,754 residents, among whom 835 infections were identified during the study period. The most common infections were urinary tract infections (UTIs; 286, 34.2%), respiratory tract infections (RTIs; 259, 31%), and skin infections (150,17.9%). Of the 259 residents with respiratory tract infections, 69 (27%) had pneumonia. Antimicrobials were prescribed for 646 (77%) of the infectious episodes. Residents with pneumonia were more likely to die than residents with other infections (4 of 69 versus 12 of 766; P=0.04). Symptoms of altered body temperature (fever, hypothermia, chills) and change in mental status also were associated with an increased risk of a fatal outcome (10 of 260 versus 6 of 575; P= 0.01) and (7 of 127 versus 9 of 708; P= 0.004). This study suggests that the most common infections among NH residents are UTIs, RTIs, and skin infections. Pneumonia, symptoms of fever, and mental status changes all were associated with increased mortality. The frequency of infections among NH residents and their impact on resident outcome highlights the need for infectious disease surveillance in this population.