Early childhood education programs have been found to effectively promote children's social and cognitive development. However, the health impact of these programs is less understood. Using a quasi-experiment of the first universal child care reform in China from 2010, this paper aims to identify whether the preschool reform produces any short-term effects on health-related outcomes of preschoolers (3-6 years old). Specifically, this reform expands access to affordable preschools that provide full-day center-based education, with school meals and essential health services on campus. I exploit the variation in the number of newly established preschools across provinces and implement difference-in-differences and triple-difference strategies. Results confirm the effectiveness of this reform by showing a strong and positive impact on preschool attendance. This paper then documents the benefits to alleviating underweight among preschoolers. Estimates show a larger effect in rural areas, suggesting that the reform narrows rural-urban disparities in education access and undernutrition prevention. I also explore the impact on caregivers’ health consciousness and find improved health-seeking behavior when children get sick.