It is well known that the indigenous peoples and tribes of the Western Hemisphere have used a variety of psychoactive preparations in a ritual context. Major nonoral dosage forms seem to be enemas (de Smet 1983), snuffs (de Smet 1985a) and fumigatories (de Smet 1985b). With respect to snuffs. there can be no doubt that the center of their ritual use lies in South America (see Table I). One of the numerous South American groups that has been reported to employ intoxicating snuffs is the Venezuelan Piaroa tribe (Wassen 1967). These tropical forest people of the Salivan family are settled along tributaries of the Orinoco in the Guiana Highlands of the Federal Territory of Amazonas (Kaplan 1975). Ethnobotanical sources only stated that the Piaroa Indians prepared snuffs from Anadenanthera seeds (von Reis Altschul 1972; Wilbert 1958: Wurdack 1958). but in the 1960's the presence of harmine in a Piaroa snuff was reported (Holmstedt & Lindgren 1967). This compound is not an Anadenanthera constituent, but a Banisteriopsis alkaloid and its occurrence in South American snuffs is rare. Consequently, the authors welcomed the opportunity to analyze two different snuffs of the Piaroa Indians that had not been analyzed before. The results of the chemical studies are presented in the second part of this article. This is preceded by an ethnobotanical and chemical overview of Piaroa and related snuffs, and followed by a pharmacological view of the constituents that were isolated .