Our study demonstrated that the exposure to aya- huasca can produce dose-dependent maternal and developmental toxicity in Wistar rats. Certainly, the data also suggest the need for additional research addressing the risk of developmental toxicity in humans exposed to ayahuasca. Our study presented the first evaluation of the toxicity of ayahuasca in animals during the gestation period. Confirmation of toxicity and risk associated with its use should be made with additional experiments, particularly with different species. The mechanisms by which these toxic effects occur in animals and whether or not the same process occurs in humans are important issues which need to be clarified.