Child Opportunity Index (COI) measures neighborhood contextual factors (education, health and environment, social and economic) that may influence child health. Such factors have been associated with hospitalizations for ambulatory care sensitive conditions (ACSC). Lower COI has been associated with higher health care utilization, yet association with rehospitalization(s) for ACSC remains unknown. Our objective is to determine the association between COI and ACSC rehospitalizations. Multicenter retrospective cohort study of children ages 0 to 17 years with a hospital admission for ambulatory care sensitive conditions in 2017 or 2018. Exposure was COI. Outcome was rehospitalization within 1 year of index admission (analyzed as any or ≥2 rehospitalization) for ACSC. Logistic regression models adjusted for age, sex, severity, and complex and mental health conditions. The study included 184 478 children. Of hospitalizations, 28.3% were by children from very low COI and 16.5% were by children from very high COI neighborhoods. In risk-adjusted models, ACSC rehospitalization was higher for children from very low COI than very high COI neighborhoods; any rehospitalization occurred for 18.7% from very low COI and 13.5% from very high COI neighborhoods (adjusted odds ratio 1.14 [1.05-1.23]), whereas ≥2 rehospitalization occurred for 4.8% from very low COI and 3.2% from very high COI neighborhoods (odds ratio 1.51 [1.29-1.75]). Children from neighborhoods with low COI had higher rehospitalizations for ACSCs. Further research is needed to understand how hospital systems can address social determinants of health in the communities they serve to prevent rehospitalizations.