For a set of 274 pesticides, the available information on basic physico-chemical properties (water solubility, vapour pressure, and Henry's law coefficient), agricultural usage in Germany (amounts sold and amounts applied) and occurrence in surface waters, bank filtrates and ground waters in the FRG was compiled. The analysis of these data confirmed that the potential of pesticide appearance in surface waters enlarges with increasing agricultural emission. However, the quality and the amount of available data did not allow a validation of the predictive value of fundamental physico-chemical variables which are used as indicators of exposure potentials for aquatic environments in hazard identification procedures and priority setting schemes. Thus, it is concluded that both registers of pesticide usage as well as systematic monitoring studies on residues in surface waters are needed in order to evaluate and improve the instruments of a predictive exposure assessment.