A comparison of plants utilized in ritual healing by two Brazilian cultures: Quilombolas and Kraho Indians. The present study deals with two ethnobotanical surveys carried out in two different segments of the Brazilian population: the first among the Krahô Indians living in Tocantins State, a Cerrado region, and the second one among the descendants of former black slaves, the Quilombolas, living in Mato Grosso State. Both populations use plants which may have effects on the central nervous system (CNS) in their ritual healing ceremonies. Field work was performed during two years by one of the authors (E. Rodrigues) utilizing methods from botany and anthropology. Information was obtained on a total of 169 plants which were utilized in the preparation of 345 prescriptions for 68 ailments seemingly of the CNS, classified as tonics, analgesics, anorectics, hallucinogens, and anxiolytics. The taxonomic families of plants used, the more common therapeutic indications and types of healing rituals are discussed.