Current understanding of the preparation and use of yopo, a hallucinogenic snuff made from the ground seeds of the Anadenanthera peregrina tree, has departed little from the accounts of scientists and travelers made over a century ago. Schultes and others have made refinements to these early accounts. While several scholars have drawn attention to the fact that little ethnographic work has been conducted to assess the ethnobotanical diversity and cultural framework of the snuff hallucinogen complex, few subsequent studies deal with botanical variations in preparation and use. This article contrasts historical accounts of yopo preparation with ethnographic data I have recently collected among the Piaroa ofsouthern Venezuela to demonstrate one way in which yopo preparation and use deviates from the basic model established by Humboldt, Spruce and Safford. Piaroa shamans include B. caapi cuttings in the preparation of yopo and consume doses of B. caapi prior to snuff inhalation concomitant with the strength of visions desired for particular tasks. I argue that the combined use of yopo and B. caapi by Piaroa shamans is pharmacologically and ethnobotanically significant, and substantiates claims of the use of admixtures in snuff; further ethnographic investigation of the snuff hallucinogen complex is necessary.