A deterministic GIS-based risk assessment model was developed to evaluate the ecological risk of pesticide spray drift on nontarget fields of sensitive crops based on pesticide use reporting data at the section level. USEPA defines pesticide spray drift as the wind-driven movement of pesticide particles in the air to unintended sites at the time of application. In order for a pesticide application to cause damage to nontarget crops growing in fields adjacent to the target field, the pesticide must be applied at the time of increased plant sensitivity. Consequently, the study of possible spray drift effects on sensitive crops is data-intensive and requires spatially- and temporally-explicit information on pesticide applications in agricultural production. Very few states with the exception of California have full pesticide use reporting databases at sufficient temporal and spatial resolution to infer the effects of pesticide spray drift on nontarget crops with any degree of accuracy and precision. In this report, the California Pesticide Use Reporting database for Fresno County in 2000 was analyzed using a deterministic GIS-based risk assessment model to quantify the potential crop acreage at risk due to unintended pesticide exposure from spray drift.