Although there are numerous studies on impact evaluation of overall health insurance, little is known on the impact of health insurance on health care utilization and out-of-pocket health care spending of children, especially in developing countries. This paper measures the impact of child health insurance on health care utilization and spending of children from 6 to 14 years old in Vietnam using two recent nationally representative surveys. Unlike previous empirical studies which found a positive effect of health insurance on health care utilization in Vietnam, we did not find a statistically significant effect of school health insurance as well as free health insurance for children on outpatient health care contacts. However, the school health insurance and free health insurance help the insured children decrease out-of-pocket spending per outpatient contact by around 14 and 26 percent, respectively.