Little is known about the effectiveness of center-based high quality educational programs for infants and toddlers, especially in low- and middle-income countries. This paper reports effects from a randomized trial of a high-quality center-based early intervention on infants and toddlers in two communities in northern Colombia. Just eight months into the program results indicate large positive effects on language, cognitive development and overall development, with girls benefitting the most. No effects were found on nutritional outcomes, socio-emotional development or the home environment.