Kombucha tea is a popular health beverage made by incubating the Kombucha mushroom in sweet black tea. Although advocates of Kombucha tea have attributed many therapeutic effects to the drink (1-3), its beneficial and/or adverse effects have not been determined scientifically. During April 1995, cases of unexplained severe illness (including one death) occurred in two persons in a rural town in northwestern Iowa who had been drinking Kombucha tea daily for approximately 2 months. Based on the findings of a preliminary investigation by the Iowa Department of Public Health (IDPH), on April 10 IDPH issued a news release recommending that persons refrain from drinking Kombucha tea until the role of the tea in the two cases of illness had been evaluated fully. This report summarizes the investigation of these cases by the IDPH, CDC, and the Food and Drug Administration (FDA).