Outbreak of fungemias by Sarocladium kiliense in eight public hospitals per intrinsic contamination of ondansetron intravenous Sarocladium kiliense is a saprophyte fungus that can cause opportunistic infections associated to invasive procedures. We report a multi-hospital nosocomial outbreak of fungemias due to this agent. Patients with positive blood culture to this agent were studied after six bloodstream infections identified in three Chilean hospitals in July 2013 were reported to Ministry of Health National Infection and Prevention Control Program. In general, there were mild clinical manifestations, without deaths attributable to the infection. Epidemiological and microbiological study identified 65 cases in 8 hospitals, mostly pediatric patients in chemotherapy. Initial studies of 94 different drugs and medical devices had negative results, until a second analysis of specific blisters and their pharmaceutical matrix selected by epidemiological criteria identified an intrinsic contamination of ondansetron blisters from a specific producer used in all the patients. A recall of contaminated ondansetron blisters was performed in all the country, after which the outbreak was contained. Surveillance and response of local and national infection prevention and control programs and laboratory support were key to control of a national multi-hospital common source outbreak due to contamination of a drug by an unusual fungus.