Relationship between interleukin-10 (IL-10) gene G-1082A (rs1800896) polymorphism and the risk of development and stages of chronic lymphoid leukemia is studied in ethnic Russian residents of the Kirov region of Russia. Associations of allele -1082A and genotypes (-1082AA/-1082AG) with the risk of chronic lymphoid leukemia are detected (OR=1.39, 95%CI=1.09-1.78 and OR=1.66, 95%CI=1.09-2.54, respectively). In addition, association of 1082AA genotype with late stages of the disease by the moment of diagnosis is detected. These data indicate that IL-10 polymorphism G-1082A may be involved in the pathogenesis of chronic lymphoid leukemia.