Data concerning the molluscicidal activity of 159 extracts from 84 Brazilian plants on Biomphalaria glabrata, the most important intermediate host of Schistosoma mansoni in Brazil, are presented. Seventy eight extracts (49,0%) showed activity against snails or eggs, but only twenty nine (18.2%) were active on both, snails and eggs. Extracts of two species (Mikania hirsutissima and Qualea multiflora) have shown to be lethals to adult snails at 10 ppm concentration.