This book is a collection of articles by a variety of authors and researchers who presented at a conference in Heidelberg in 2008. It has since been supplemented with several additional sources. Apart from not including a comprehensive index, the editors have done well in making the volume systematic and complete, and it is organized as follows. The first section covers the history of Ayahuasca's use. After an article on the early history of Ayahuasca, there is one for each of the main “Ayahuasca-churches” that began in Brazil (União do Vegetal (UDV) and Santo Daime). Next is an article on its use in Europe, followed by three discussions of the “Ayahuasca-tourism” phenomenon, and related uses. These are of interest because of their contrasting conclusions and opinions. The second section includes a collection of research papers and literature reviews, which together comprise a rather complete review of pharmacological research on the safety of Ayahuasca. Many of these studies seem to be well designed, and several include quantitative data in the reports. Although the results indicate no apparent safety issues associated with Ayahuasca itself, other articles in this book point out that much of the urban use of Ayahuasca involves preparations by unqualified individuals, and that this presents its own risks. Indeed, the UDV must be so careful in its administration of Ayahuasca that even dietary restrictions are required. Furthermore, the reader should be aware that, since the time of the Heidelberg conference, research has shown neurobehavioral changes in rat offspring whose mothers were treated with Ayahuasca during pregnancy (Oliveira et al., 2010, 2011). While this does not, of course, necessarily imply a similar effect in humans, it should at the least inspire caution (and further research). Finally, very little is known about possible chronic effects of long-term Ayahuasca use. The section ends with three articles describing possible medicinal uses, which are far from conclusive but form the basis for interesting topics for further research, especially by authors in this journal. The third section recounts the court cases and legislation surrounding Ayahuasca internationally. Again, the organization is systematic and complete. The first article is on the changing nature of drug laws in Brazil. The next two are descriptions of the legalization of Ayahuasca for religious purposes in the US, first for the UDV then for Santo Daime. The latter underwent a lengthy process which was very similar to that used by the UDV earlier. The UDV successfully cited religious freedom, and the counterarguments by the government were considered irrelevant. Also, many important organizations wrote on behalf of the UDV, including the American Civil Liberties Union and several prominent mainstream religious groups. According to Santo Daime, the church now works closely with Drug Enforcement officials, because it is of mutual interest to assure that none of the imported Ayahuasca is diverted for sacrilegious (illegal) purposes. Next are articles describing the legal situation in Canada, the Netherlands, Germany, France, Spain, and Italy. The book ends with an “account of judicial reasoning” in cases involving religious use of contraband substances.