The Worldwide Survey of Health Related Behaviors is administered periodically to a probability sample of military personnel. Earlier reports of these surveys suggested that illicit drug use was highest among the lowest ranking personnel. This paper reports a secondary analysis of the 1992 and 1995 surveys of the lowest ranking personnel. The results suggested that in general illicit drug users tended also to use alcohol, smokeless tobacco, and cigarettes. Heavy drinkers were more likely than light drinkers to use illicit drugs. No such relationship was observed between illicit drug use and the level of use of cigarettes or smokeless tobacco. Moreover, among the heavy drinkers, illicit drug users were especially likely to use cigarettes and among males, smokeless tobacco. The relevance of these results to military policies toward illicit drug use is discussed.