Ayahuasca, which originates from the Amazon Basin, is a psychoactive brew of two components. Its active agents are betacarboline and tryptamine derivatives. Near the spring of the Amazon River this brew is still a central component of many healing and tribal rituals. During the past few decades, the substance has become known among both laymen and scientistss and nowadays its use is spreading all over in Europe. In the present paper we give an overview of the scientific research and describe ayahuasca's main features, the main questions raised over its use, the risk factors and potential benefits. A growing number of scientific results seem to support the psychotherapeutic potential of ayahuasca, which has a strong serotonergic effect, whereas studies on its effect on the immune system also raise the possibility that certain ethno-medical observations can be scientifically proved.