Objective To explore the effect of environmental risk factors in pregnancy on the incidence of childhood leukemia. Methods Fifty-five children with leukemia in our hospital from January 2012 to January 2015 were selected as the leukemia group, and 55 children having health examination in the same period were selected as the control group. Univariate and logistic multivariate analyses were used to analyze the effect of maternal environmental risk factors on childhood leukemia. Results Logistic multivariate analysis showed that maternal exposure to chemicals and paint, previous miscarriage, cold during pregnancy, father exposure to diesel or gasoline and exposure to paint were the risk factors for childhood leukemia (P < 0.05). Conclusions Maternal exposure to chemicals, paint, past history of abortion, pregnancy cold, father exposure to diesel or gasoline, and paint are the risk factors of childhood leukemia. Therefore the health education of parents should be strengthened during pregnancy to reduce the incidence of leukemia in children.