We conducted an exploratory study of young-onset Parkinson's disease (YOPD) to examine occupational and environmental factors associated with disease risk. This case-control study included 63 YOPD patients (diagnosis on or before age 50); controls (n = 68) were diagnosed with rheumatoid arthritis. Crude odds ratios (ORs) were computed to identify exposure variables for logistic regression analyses. After controlling for the variables of race, educational level, sex, age, age at diagnosis, and family history of Parkinson's disease (PD), PD was positively associated with insecticide exposure (OR = 5.75, p < 0.001), past residency in a fumigated house (OR = 5.25, p = 0.046), herbicide exposure (OR = 3.22, p = 0.033), rural residency at time of diagnosis (OR = 2.72, p = 0.027), and nuts and seed eating 10 years before diagnosis (OR = 1.49, p = 0.021). PD was inversely associated with cigarette smoking at 5 years (OR = 0.50, p = 0.027), 10 years (OR = 0.43, p = 0.012), and 15 years (OR = 0.37, p = 0.005) before diagnosis, farm residency (OR = 0.38, p = 0.018), and exposure to dimethyl sulfoxide (OR = 0.10, p < 0.001). These findings are consistent with hypotheses linking PD to exposure to pesticide agents.