ABSTRACTBACKGROUNDThe purpose of this study was to assess the effects of the Bienestar/NEEMA Coordinated School Health Program (BN CSHP) on cardiorespiratory fitness (CRF) of preschool children.METHODSA cluster randomized trial was conducted of preschools in South Texas. Of 48 eligible schools, 28 were randomly assigned (14 intervention, 14 control). Family demographics and household health characteristics were collected from parents and CRF from children. Generalized linear mixed model (GLMM) was used to analyze the data.RESULTSFamily demographics, household health characteristics, and children's weight, obesity prevalence, and sedentary activity of the control group were similar to the intervention group at baseline. After adjusting for covariates, the number of laps ran by children in the control group increased by 23% (CI: −5% to 60%) per each data collection period compared with 53% (CI: 7% to 119%) in the intervention group.IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITYState mandates, parent engagement, and funding are key for designing effective health and Physical Education (PE) programs.CONCLUSIONChildren in the BN CSHP, compared to those in the control group, had a significantly higher increase in their CRF. This finding is important because of the health benefits of CRF in children. ClinicalTrials.gov Identifier: NCT05501392.