This ethnographic study discusses the use of ayahuasca by contemporary urban Brazilians, in the city of Rio de Janeiro. Ayahuasca, a Peruvian Quechua word meaning “the vine of the spirits”, is one of the most powerful entheogens (formerly called hallucinogens) found on the planet. In the last twelve years there has been an enormous increase in the use of this brew among Brazilian urbanites. This study investigates how ayahuasca affects the core religious beliefs and spirituality in every human; how contemporary Cariocas - inhabitants of Rio de Janeiro city - relate to the drink; how contemporary Cariocas are re-creating traditional shamanic ayahuasca rituals in their own environment, and how they interpret these rituals. For some, ayahuasca is a religion; and for all, a path toward self-knowledge.