Background Layperson cardiopulmonary resuscitation ( CPR ) is a crucial intervention for patients with out-of-hospital cardiac arrest ( OHCA ). Although a sex disparity in receiving layperson CPR (ie, female patients were less likely to receive layperson CPR ) has been reported in adults, there are few data in the pediatric population, and we therefore investigated sex differences in receiving layperson CPR in pediatric patients with OHCA . Methods and Results From the All-Japan Utstein Registry, a prospective, nationwide, population-based OHCA database, we included pediatric patients (≤17 years) with layperson-witnessed OHCA from 2005 through 2015. The primary outcome was receiving layperson CPR . Patient sex was the main exposure. We fitted multivariable logistic regression models to examine associations between patient sex and receiving layperson CPR . We included a total of 4525 pediatric patients with layperson-witnessed OHCA in this study, 1669 (36.9%) of whom were female. Female patients received layperson CPR more often than male patients (831/1669 [49.8%] versus 1336/2856 [46.8%], P=0.05). After adjustment for age, time of day of arrest, year, witnesses persons, and dispatcher CPR instruction, the sex difference in receiving layperson CPR was not significant (adjusted odds ratio for female subjects 1.14, 95% CI, 0.996-1.31). Conclusions In a pediatric population, female patients with layperson-witnessed OHCA received layperson CPR more often than male patients. After adjustment for covariates, there was no significant association between patient sex and receiving layperson CPR .