Potential hazards associated with the use of agricultural pesticides are a growing concern for society. We describe the relationships between the mortality data for cancers of the brain, the lymphatic tissues and leukemia, and the spatial distribution of agricultural pesticide use for 34 drainage basins in Quebec, from 1976-1985. The basins were grouped into three categories (low, intermediate, and high exposure) according to the level of sales of pesticides. For cancers of the lymphatic tissues among women 35 to 64 years of age, a high relative risk (RR) was observed (RR = 1.91, 95% Confidence Interval = 1.14, 3.18) in basins highly exposed to pesticides compared to those with low exposure. Analysis of correlation for this cancer at 34 basins showed significant associations between geographical distributions of the Standardized Mortality Ratio (SMR) and those of numerous variables indicative of pesticide use in agriculture. Agreement between the results for mortality data in this exploratory study and the results from another study on cancer incidence data for 1982-1983, supports the hypothesis of a potential relationship between the use of pesticides in agriculture and cancer of the lymphatic tissues.