BACKGROUND: Children born with congenital diaphragmatic hernia (CDH) are at risk of poor developmental outcomes. This study aimed to clarify the motor and functional characteristics of school-age CDH survivors and identify perinatal factors associated with motor function deficits. METHODS: Motor function was comprehensively assessed in CDH survivors aged 6-10 years (CDH group, n=24) and in age- and sex-matched controls (n=72). Assessments included physical activity time, grip strength, the five times sit-to-stand test, one-leg standing time, 6 min walking distance and gait ability using a three-dimensional gait analysis. In the CDH group, correlations between perinatal factors and motor function outcomes were analysed. RESULTS: In the CDH group, all children had isolated CDH. Three were extracorporeal membrane oxygenation (ECMO) treated and 21 were non-ECMO treated. The CDH group exhibited shorter stature, lower weight and reduced physical activity time than the controls. They also showed significantly lower grip strength, longer five times sit-to-stand test time, shorter one-leg standing time and decreased 6 min walking distance. No significant differences were found between the two groups regarding walking speed, step length or Gait Deviation Index. Within the CDH group, a higher observed-to-expected lung area-to-head circumference ratio (o/e LHR) was positively correlated with better grip strength. CONCLUSIONS: School-age survivors of CDH are at risk of impaired motor function. Particularly, grip strength measurement is crucial for those born with a low o/e LHR. Implementing follow-up and intervention programmes focused on improving limb muscle strength, balance, and endurance, and promoting adequate physical activity may enhance motor function.