The basic role of groundwater as a primary source of good-quality water supply for human consumption justifies the growing public concern about the possibility of contamination of this irreplaceable resource, which may cause, its use for drinking purposes to be severely limited. The task of protecting groundwater in order to provide good quality water for drinking purposes has been faced with extremely different approaches. Even in the field of hydrogeologic studies, the conceptual instruments needed to evaluate groundwater vulnerability and to contribute to the prediction of pesticide occurrence in groundwater are available at a suitable level of reliability. From a wider perspective of prevention, the protection of environmental resources from potentially dangerous chemicals, particularly the protection of groundwater from pesticides, must be included in a general strategy of land use management. The scientific development has produced enough information and know-how to understand the problem of pesticide risk and to suggest some possible solutions, even if with some uncertainties.