In the past several years there has been a dramatic proliferation of drug-related sites on the Internet. This article reviews the information found at selected Inte et drug information libraries, and comments on its accuracy and implications. Drug-related sites were found by initially performing an Internet search on "psychoactive drugs" and then exploring links among the sites identified. Sites were chosen on the basis of comprehensiveness of information and positive or tolerant attitude tow d drug use. While all classes of drugs are discussed at these sites, the primary foci of interest are synthetic and naturally occurring hallucinogens. Many of the biological materials discussed are legal and readily available. Information surveyed at these sites was largely accurate regarding the effects of various substances and biological sources of psychoactive compounds. Conclusions: Internet drug information libraries contain large amounts of information about a wide variety of drugs, including previously little-known biological sources of hallucinogens. The availability of this information could have significant effects on patterns of drug use. Keywords: drug abuse, drug usage, Internet, hallucinogens