While drug use has declined in the Navy and the Marine Corps in comparison to the civilian community, the military services have much less margin for error when it comes to drugs. In 1991, 12.6 million (4 percent) of the total U.S. population used illicit drugs. That same year, the Navy arrested 7,714 (1 percent) for drug offenses or positive urinalysis tests. Of the 7,714 Navy drug users, 2,296 (29.8 percent) were cocaine users. In response to the drug problem, NISCOM uses an aggressive investigative approach, coupled with education and prevention programs, to assist Navy efforts in reducing the demand for and flow of drugs. Key factors affecting the drug involvement of Navy personnel in the future will be the economy and Department of Defense force reductions. Statistics on Navy drug suspects are provided for fiscal years 1990 and 1991 and on cases investigated and dispositions. The use of polygraph examinations by NISCOM is discussed, as well as forensic laboratory and urinalysis procedures. Proactive drug control measures are also addressed, such as suppression, eradication, special, and undercover operations and the use of military dogs. Regional trends in NISCOM investigations are reviewed. Tables and figures