The dry powder from Synadenium grantii was screened for molluscicidal activity against B.elaxandria and L.natalensis. The comparative susceptibili ties of B.alexandrina and L.natalensis to the toxic action of the different solvents were determined. Investigation under the effect of some simulat ed field conditions indicated that the activity of the plant is resistant to the effect of sun light, mud and different temperatures (16-30°C). Whereas the activity was increased under acidic pH, it was slightly depressed in alkline media.