Objective. To describe the results of ten years of nosocomial infection (NI) surveillance in an oncology center. Material and methods. This is a descriptive study of the Infection Control and Surveillance Program Committee at the Instituto Nacional de Cancerología, conducted in 1997. From June 1986 to December 1996, we surveyed 62 733 hospital discharge records. Criteria used to classify nosocomial infections were those outlined in 1972 by the Centers for Disease Control and Prevention, Atlanta (GA). Survey data were collected through review of microbiology chart records and of hospital chart records of febrile patients, patients receiving antibiotics, and patients visited after surgery. We calculated the rates of NI as the number of infections/100 discharges. Results. The rate of NI per 100