Persistence is a critical factor that significantly predicts life outcomes. Although individual differences in persistence emerge early in life, the knowledge of effective strategies for cultivating persistence in young children remains limited. Based on these two studies, we suggest that emotional validation, defined as the acceptance of emotions without judgment, is a beneficial technique for promoting persistence in the wake of frustration. Study 1 examined 150 parents of children aged 4-6 years and found that parents' tendency to validate their children's emotions was positively associated with children's trait persistence. We conducted a randomized experiment (N = 93, aged 4-6 years) in Study 2 to establish a causal relationship between emotional validation and persistence in preschoolers. Children who received emotional validation feedback (n = 31) exhibited higher levels of persistence than those who received emotional invalidation (n = 31) and no feedback (baseline, n = 31) on a frustrating task. The persistence between the emotional invalidation and no-feedback conditions was not statistically different. This finding highlights the vital role of emotional validation in promoting persistence in children at trait and state levels. In summary, this study offers a compelling strategy for empowering young children with resilience and determination when they encounter challenges.