This article addresses some of the recent controversy over the role of psychoactive substances in the !Kung Bushmen healing ceremonies and trance induction. Although some contemporary works on the !Kung and their healing ceremonies give no evidence of the use of psychoactive plants, an examination of the available biochemical and pharmacological literature on the properties of these plants indicates that most contain psychoactive or toxic substances that are likely to have trance-inducing properties. Almost half of the !Kung medicine plants contain psychoactive substances or have toxic pproperties, and a similarly large group of these plants has psychoactive or toxic properties in related species. Although recent reports have shown little concern with the use of psychoactive substances, the earlier literature illustrated a major concern with their use in !Kung Bushmen trance and healing. This contrast with more recent research suggests a decline in the use of psychoactive plants in the recent past. This decline is examined with respect to changes in the !Kung Bushmen society and how altitudes in the United States regarding drug use may have influenced investigators and their research reports.