In Ciro Guerra’s film Embrace of the Serpent (2015), cultural exchanges between the central characters reveal the origin narratives and the curative power of plants valued by Indigenous cultures of the Amazon. This article analyzes how Embrace of the Serpent expresses Indigenous rationality in the origin narratives as the shaman Karamakate confronts Western travelers and scientists. For these Indigenous cultures, knowledge and its reproduction are equivalent to ancestral songs and rituals such as the ceremony of the Ayahuasca. This article supports these ideas not in a filmic analysis but by exploring central aspects and scenes in the film associated with intercultural exchanges and the ritual of Ayahuasca. Finally, Embrace of the Serpent highlights the difficulty of distinguishing between the rationality of orality and writing with which Native cultures of the Americas understand the world that surrounds them.