The evidence that investments in early child development can pay high, long-term dividends, is mounting, both in developed and developing countries. However, recent meta-analysis identified very few studies in developing countries. The authors report on the evaluation impact of a low-cost, community-based parent training program for early child development (ECD) implemented in four states across Mexico. This research study explored: (1) The impact of this low-cost, parent-focused ECD program on the physical, cognitive, and socio-emotional development of children 0-4 years?; (2) The impact of the program on the knowledge and behaviors of parents of children 0-4?; and (3) The differential impact of the program in communities with other significant ECD initiatives? The program, implemented by the government, provided out-of-school training for parents and caregivers of children aged 0-4, to improve their competencies and practices in caring for children and contribute to the children's comprehensive development and school readiness. The results showed participating children had higher scores in all five areas of child development. Also the low-cost, community-based parenting program for parents of young children had significant impacts both on child development and on observed parent behavior. Because parent behaviors affect child development throughout the development process, these changes have a particular potential to translate into long-term, sustained gains in child development.