Gamma hydroxy butyrate (GHB) is a central nervous system depressant approved as an anaesthetic in some countries; however, with the exception of investigational research, it is not approved for any use in the United States. Primary groups using GHB include party and nightclub attendees and bodybuilders. In addition, GHB is one of several agents characterized as a "date rape" drug. During August 1995-September 1996, poison control centers in New York and Texas received reports of 69 acute poisonings and one death attributed to ingestion of GHB. This report describes two cases and summarizes the investigations of GHB use in Texas and New York. The findings of these investigations underscore the health hazards associated with use of GHB.