This article is an overview of social and legal differences in the United States and in Japan that are related to patterns of current drug abuse epidemics in these countries. These two nations have drug abuse problems with different histories and take different approaches currently to handling illicit drug marketing and use. Histories of opiate and cocaine abuse in the United States and of stimulant and inhalant abuse in Japan are discussed. The United States has experienced three heroin epidemics in the last three decades; cocaine addiction began to merit national concern by the end of the 1980s. In Japan, the first methamphetamine epidemic began after World War II; it was controlled in the 1950s. The current inhalant epidemic began in the late 1960s and was followed by the second methamphetamine epidemic that began in 1970; both are continuing to the present. The criminal justice system is always given first consideration when assessing societal measures employed to reduce drug use. Legal penalties for illicit drug offenses reflect the societal differences of these two nations with respect to the seriousness of particular types of crimes. Characteristics of the health care system of a nation may also influence patterns of drug abuse, particularly where functions of criminal justice and health care systems overlap. Health care systems in the United States and in Japan are based on different treatment philosophies and patients' expectations; these differences are discussed along with explanations of their potential influence on the epidemiology of drug abuse.