We have assessed the ability of a range of pesticide, site and climate parameters to discriminate between detected and non-detected pesticides as observed by long-term monitoring data of pesticide use and groundwater occurrence in a small catchment in southern Sweden. Of seventeen investigated parameters, six demonstrated such an ability: dosage applied, the Henry's Law Constant (HLC), the octanol–water partitioning coefficient (log Pow), the amount of precipitation the week before application, the amount of precipitation the month after application, and the substance degradation potential (DT50). The apparent influence of the investigated parameters on pesticide occurrence in groundwater, and their apparent suitability as descriptive parameters in terms of assessment of related risks, is accordingly discussed.