Because of the large range of circumstances (such as soil-type, climatic zone, and local agricultural practice) in which pesticides are applied, it is impossible to test fully the environmental fate of a new pesticide being considered for registration. Thus, risk assessors should make best use of modern techniques and all relevant information to make their assessments. This paper discusses the use of statistical methods which use pesticide chemical properties to predict environmental fate. Using US data, a logistic regression approach can be used to estimate the probability that a compound leaches to groundwater based on adsorption (Koc) and degradation (DT50) parameters. An advantage is that both properties are already required to be measured as part of the present pesticide registration process. For UK groundwater monitoring, precise pesticide soil properties are not measured. However, further methods using UK data also indicate that polluting and non-polluting compounds may be distinguished on the basis of these chemical properties. The techniques presented can be used in conjunction with pesticide usage statistics to inform the selection of priority pollutants, to enable monitoring programmes to become more focused, to assess the risk associated with new compounds, and to identify those at high risk of contaminating groundwater.