The article focuses on countries and areas of South-East Asia, which are seriously affected by drug abuse and the problems associated with it. Opium has traditionally been used for treating illnesses and alleviating physical and mental stress, as well as for recreational and social purposes. The prohibition of the sale and use of opium in Burma, Hong Kong, Malaysia, Singapore and Thailand forced many habitual opium users to switch to heroin. Over the past two decades there has been an increasing trend towards drug use, often involving experimentation with more than one substance, among youth in and out of school. For example, a survey of students at teachers' colleges in northern Thailand showed that at some time in their lives 30-40 per cent of the male respondents and 3-6 per cent of the female respondents had used cannabis, and that 18-20 per cent of the males and 12-27 per cent of the females had sniffed volatile solvents. The same survey showed that 5-10 per cent of both the males and females had used stimulants and nearly 2 per cent had used heroin. During the 1970s the abuse of heroin and other opiates emerged as a serious problem of epidemic nature, predominantly affecting young people in many countries of South-East Asia. While opiates, including heroin, have been abused by inhaling and by smoking, there has recently been an increasing trend towards injecting heroin of high purity (80-90 per cent pure heroin). Heroin addiction spread first to the populations of capital cities and then to other cities and towns and even to the hill tribes, as studies in Thailand have revealed. Most recent studies have shown that heroin abuse has spread further in Asia, both socially and geographically, involving such countries as India and Sri Lanka, which had no previous experience with the problem. Studies have also shown that the abuse of manufactured psychotropic substances has been increasing and that heroin addicts resort to these substances when heroin is difficult to find. The article also briefly reviews the history of opium use in China and the history of drug abuse in Japan, particularly with regard to the problem of methamphetamine abuse, which has appeared in two epidemic-like waves. The first followed the end of the Second World War and disappeared at the end of the 1950s; the second reappeared in 1975 and since then has gradually been increasing in size.