Ayahuasca is a botanical hallucinogenic preparation traditionally used for ritual and therapeutic purposes by native populations of the Northwestern Amazon. In the last decades, ayahuasca use has spread to Europe, the United States, Asia, and Africa, and interest in the possible therapeutic uses of ayahuasca for treating anxiety and mood disorder and substance-use disorders has increased both among the general public and the scientific community. Indeed, preclinical, observational, and preliminary clinical studies have corroborated some of these findings. In the present article, we present an overview of these studies and highlight the current uses of ayahuasca in neuroscience, such as a tool in the investigation of the neural basis of introspection and other complex cognitive processes.