This book is inspired by the 2013 Psychedelic Science Conference, held in Oakland, California. The Multidisciplinary Association for Psychedelic Studies (MAPS) promoted the conference in cooperation with the Heffter Research Institute, the Beckley Foundation, and the Council on Spiritual Practices. The event convened over 1,900 people from all over the world, including anthropologists, medical doctors, lawyers, psychiatrists, and psychologists, and members of the general public. It was wide ranging, with a focus on the scientific research into the medical use of psychedelics. Research topics included MDMA-assisted therapy for post-traumatic stress disorder (PTSD), ibogaine for opiate addiction, and LSD and psilocybin for end-of life anxiety, among others. The conference was composed of three tracks: (1) the Clinical Research Track; (2) an Interdisciplinary Track, with a mix of topics, including psychedelic psychotherapy, non-clinical research, arts and culture, and medical marijuana; and (3) the Ayahuasca Track. Beatriz Caiuby Labate was the organizer of the Ayahuasca Track. This volume brings together a select collection of six presentations from this track, and is complemented by seven additional relevant contributions. Ayahuasca (generally composed of Banisteriopsis caapi and Psychotria viridis) is a psychoactive brew of Amazonian origin that, over the last few decades, has caught the attention of many patients, healers, and researchers. The beverage’s transformation into an internationally known ‘‘medicine’’ for physical, psychological, and spiritual ills has stirred up controversy over its use, and whether it ought to be banned or revered. The ritual and therapeutic uses of ayahuasca vary greatly by country; whereas different forms of the religious use of ayahuasca have been recognized as legitimate in some parts of the world, the therapeutic use of ayahuasca has not gained official acceptance beyond the limits of the Amazon rainforest. This interdisciplinary collection presents a series of perspectives on the therapeutic potential of the ritual and clinical use of ayahuasca in the treatment and management of various diseases and ailments especially, its role in psychological well being and substance dependence. Anthropological and biomedical data on the use of ayahuasca for treating depression, PTSD, and substance dependence in different settings, such as indigenous contexts, neo-shamanic rituals, contemporary therapeutic circles, and in the ayahuasca religions of Santo Daime and União do Vegetal, in both South and North America, are presented and critiqued. The texts in this volume also discuss methodological, ethical, and political considerations for current and future research in this area. With this work, we aim to bring the therapeutic use of ayahuasca to a new level of public examination and academic debate, as well as to fill in gaps in the current literature. Though multiple anecdotal reports on the therapeutic use of ayahuasca exist, there has been no systematic and dense reflection on the topic thus far. We hope this collection offers an important advancement in this discussion, and helps to inform international regulation on ayahuasca use based on the scientific study of this substance’s relative benefits and harms. We also hope this book proves to be a source of inspiration for further research in this emergent field of studies. We would like to thank the Center for Economic Research and EducationCIDE Región Centro in Aguascalientes, Mexico; MAPS in Santa Cruz, CA; and Anton Bilton, Tyringham, England, for their support. We would also like to express our gratitude to the contributors to the volume. Our colleagues Bob Jesse, Brian T. Anderson, Rafael Guimarães dos Santos, José Carlos Bouso, Michael Winkelman, and Mitchell B. Liester provided important help during the process of editing this collection. Finally, we are grateful to Springer for its openness to this frequently stigmatized topic.