Background: This study examined what factors affected a complete examination of infant health checkup. Methods: We used Korean national health insur\-ance claim data of 2,936,650 infants, taking examination in 2012. These claim data included enrollment status of householders and records of infant health checkup from 2008 to 2013. Results: Our results shows that for infant characteristics, the likelihood of complete ex\-amination of infant health checkup is significantly lower in female, older aged, and handicapped ones. For householder characteris\-tics, the likelihood of complete examination of infant health checkup is also significantly lower in female, older group and self-em\-ployed ones. For household characteristics, the likelihood of complete examination is also significantly lower in single-parent fami\-lies, multi-cultural families, parent with unexperienced health checkup and lower monthly premiums. Conclusion: It is necessary to support an additional use-guide and follow-up management services to improve incomplete examination of infant health checkup.