Volatile substance abuse (VSA) (glue sniffing, inhalant abuse, solvent abuse), the deliberate inhalation of volatile substances in order to achieve intoxication, has now been reported from most parts of the world, mainly among adolescents, individuals living in remote communities and those whose occupations give ready access to abusable substances. Solvents from contact adhesives, notably toluene, petrol (gasoline), halogenated solvents, volatile hydrocarbons such as those found in cigarette lighter refills, aerosol propellants, halocarbon fire extinguishers, and inhalational anaesthetics may be abused in this way. VSA gives rise to dose-related effects similar to those of other hypnosedatives. Small doses can rapidly lead to euphoria and other disturbances of behaviour similar to those caused by ethanol (alcohol), and may also induce delusions and hallucinations. Higher doses may produce life-threatening effects such as convulsions and coma. Death may ensue indirectly after, for example, inhalation of vomit, or from direct cardiac or central nervous system toxicity. Chronic abuse of toluene-containing products and of chlorinated solvents such as 1,1,1-trichloroethane, for example, can produce severe organ damage, especially in the liver, kidneys, and brain. Drunken behaviour, unexplained listlessness, anorexia and moodiness may result from VSA, especially in children and adolescents. The hair, breath and clothing may smell of solvent, and empty adhesive tubes or other containers, potato crisp bags, cigarette lighter refills, and aerosol spray cans are often found. Toxicological examination of blood and tissue specimens is especially important in confirming a diagnosis of sudden VSA-related death. The development and evaluation of strategies for the treatment of chronic abusers and for prevention are major challenges for the future.