Ethnopharmacology has been re-discovered by the end of the XX Century, and beginnings of the XXI Century. Ethnopharmacology has showed a new source for discovery and development of new drugs, if compared with other methods of search (random, chemicosystematic, philogenetics). The great challenge is also redeem the time and preserve popular knowledgement about medical plants1. We realize an ethnopharmacological approach in Ilha Grande, Rio de Janeiro, interviewing local population about their culture and uses of medical plants, and the transmission of this knowledgement for the next generation.