The evidence presented in this paper indicates the use of a variety of psychoactive plants by the Chavín people. In the absence of psychoactive plant remains, Chavín iconography provides clear evidence for the use of Trichocereus (San Pedro) and Brugmansia species. San Pedro cactus representations are seen in Cupisnique ceramics and in relief sculpture of the Old Temple. Depictions of Brugmansia flowers, leaves, and seed capsules are apparent in the Tello obelisk. Evidence for the use of Anadenanthera is suggested by the presence of probable snuffing paraphernalia at Chavín-related sites, by its representation on painted textiles, as well as by early documentations of its use in northern Peru (ca. 1200 B.C.).The habitat of this genus extends to the upper Marañon River drainage, an area located within the Chavín sphere of influence, increasing the likelihood of its availability. Effigy vessels in the form of coca chewers attest to the use of coca leaves during Chavín times in northern Peru; two coca varieties were likely available at Chavín de Huántar: E. coca var. coca and E.novogranatense var.truxillense.It is highly probable that tobacco was available to the Chavín people, but the art does not include apparent references to its use. Chavín art,it can be concluded,is largely constructed by a metaphoric process, which ranges from complex series, such as the metamorphosis of the primary personage on the Raimondi stela, to simple substitutions such as the transformation of hair into snakes seen in numerous Chavín personages. This represents the outcome of gradual processes of transformation in form and meaning in order to articulate or encode diverse aspects of the ecstatic experience. In general, shamanic ideologies are also expressed through metaphors. This trope is apt to describe situations of metamorphoses, because of its capacity to transfer qualities proper to one object onto another. Sometimes the metaphor implies a permanent or constant equation such as in the Huichol deer/ peyote complex that equates the deer with the peyote cactus and the quest for peyote at Wirikúta with a deer hunt (Furst 1990:146). In other cases the metaphor’s function is ephemeral and variable, as in the long shamanic chants of María Sabina, the renowned Mazatec shaman, with its constantly accumulating identities and shifting functions: I am a daylight woman I am a Moon woman, says I am a Morning Star woman I am a God Star woman . . . I am the woman who works, says I am the woman beneath the dripping tree, says . . . I am the woman who looks into the inside of things, says . . . [Estrada 1981:65] Compositional devices and organizational structures such as repetition, accumulation of motifs, and reversible and anatropic imagery demonstrate clear parallels with the ecstatic state. Issues of transformation and skeletonization provide links to shamanic ideas. Monumental entrances, multilevel plazas, and subterranean passages contributed to the performative qualities inherent in ceremonial activities. The display of imagery directly related to psychoactive plant use in public monumental stone sculpture and architectural decoration, such as the tenon heads and the relief carving in the Old Temple, provides strong support for the importance of these plants in the ritual life of this archaeological culture.