Cyanide is one of the most lethal and rapidly acting poisons known to man. Clinical symptoms can occur within minutes of exposure, and exposure to this toxicant can be fatal. Since terrorists have threatened and attempted to contaminate the U.S. drinking water using cyanide, this paper discusses important characteristics of cyanide that water utilities should understand. They include: what cyanic compounds water utilities should be concerned about; what health affects would be noticeable during cyanide poisoning; what water quality changes would be noticeable when cyanide contamination occurred; what are the available commercial detection equipment for drinking water; and, how to treat water containing cyanide. This paper also includes results from a literature study. Specific water utility recommendations are provided. Includes 54 references, tables, figure.