This article presents the results of an ethnographic study (based on the perspective of observant participation) performed by the religion known as Uniao do Vegetal (UDV), with the locus of the Metropolitan Region of Belém (PA). A religion native to the Amazon, the UDV is ranked as one of the three main lines of Religions of Ayahuasca, which, among other similarities, have in common the use of entheogenic tea decoction derived from two species: the Banisteriopsis caapi (mariri) and leaf Psychotria viridis (chacrona). Introducing methodological approach to issues relating to use of oral language as the only way of transmission of teachings, as well as aspects and memory settings for this group, the study investigated how these categories and their interrelationship contributes to shaping the worldview this group – as a way of contributing to the framework of research on religions and religious practices in the Amazon. KEYWORDS: União do Vegetal (UDV); orality; memory; knowledge; ethnography.