Objective To investigate the relationship between household insecticides exposure and the incidence of childhood acute leukemia (AL) for different development periods of children. Methods We interviewed parents/guardians of children from case group and control group which matched the case group with respect to gender, age, and location of residence. Information on normal sociodemographic characteristics of subjects and household insecticides usage during their different development periods was collected. The results of investigation were processed by conditional logistic regression analysis and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Results The rate of household insecticides usage of case group was higher than that of the control group. Mainly used insecticides were mosquito repellent and cockroach killer. The incidence of childhood AL may increase when household insecticides were used (OR=6.3, 95%CI: 1.4-28.7) and cockroach killer was used (OR=7.8, 95%CI: 1.6-37.7) during the period of 0-3 years old, and mosquito repellent was used (OR=3.3, 95%CI: 1.1-10.2) during the most resent year. Besides, the incidence of childhood AL might also increase when the usage frequency of mosquito repellent (OR=5.8, 95%CI: 1.1, 30.1) and cockroach killer (OR=8.9, 95%CI: 1.5, 52.2) increased. Conclusion Household insecticides exposure during the period of 0-3 years old

and the most resent year may increase the risk of childhood AL.