Millions of children are at risk for developmental deficits in low and-middle-income countries (LMICs).Reviews find that psychosocial interventions for children aged <3 years improve short-run child cognition and language (0.28–0.47 SD). Similarly, a meta-regression analysis of 54 preschool interventions for children aged ≥3 years found significant improvements in children’s cognitive skills (0.15 SD), executive functioning, social–emotional learning, and behavior (0.12 SD). Only 18 of these interventions were from LMICs, with 2 from India, which has the world’s largest population of children attending preschool (36 million children enrolled in Integrated Childhood Development Services [ICDS]). Interventions have had benefits in math and language. However, a survey of 298 Indian preschools found generally poor quality. Although short-run impacts of some interventions fade, some rigorous studies with long-term follow-ups found later benefits in educational attainment, reduced crime, and increased income.