A case-control study was conducted in 620 cases of hematological malignancies and in 1,240 age- and sex-matched controls in order to verify the possible association between occupation, toxic substances exposure, and the risk of hematological neoplasias. The results demonstrate that farmers and industrial workers have a significant risk for hematological malignancies. Exposure to asbestos, aromatic hydrocarbons, fertilizers, mineral oils, pesticides, and radiations is associated with a significant increase in the risk for these malignant diseases. These data are in agreement with previously reported data, and require a confirmation in larger, prospective studies.