A case-control study was performed in southwestern France in order to assess the relationship between pesticide exposure and Parkinson's disease (PD) in the elderly. During the period from 1997 to 1999, 84 cases were recruited together with 252 population-based controls. Experts in occupational health reviewed job codes and provided pesticide exposure levels, making it possible to calculate cumulated exposure lifelong for individuals. Environmental pesticide exposure was considered in relation to the place of residence. A positive association was found with occupational pesticide exposure (odds ratio = 2.2, 95% confidence interval 1.1-4.3) in conditional logistic multiple regression analysis taking into account age, sex, educational level and smoking; however, no clear dose relationship was found. Our results support the hypothesis of an association between occupational pesticide exposure and PD and point to the need to investigate the role of fungicides, for which toxicological hypotheses exist.