Can at-scale, government-implemented parent training programs improve parenting practices and child development outcomes? This article presents evidence on the effects of a low-cost, group-based early childhood education program that provided parent training and direct child stimulation in rural communities, evaluated in six Mexican states. Despite limited take-up, the program had positive impacts on observed parent behaviors in its first year. An index of observed parenting behaviors increased by 0.20 standard deviations, with larger effects (0.32 standard deviations) for parents of the youngest children (ages 0-35 months). An index of impacts on child development showed no statistically significantly effects, but certain aspects of child development showed suggestive evidence of positive impacts in the first year. For both parenting practices and child development, effect sizes were smaller and not statistically significant in the second year. The fade-out of effects is consistent with existing literature on parenting programs. Impacts of the program on child development were not significantly different for girls versus boys or for younger versus older children. These results suggest that parent training can be implemented at low cost, although design changes to improve implementation and take-up would likely be needed to generate sustained impacts on parenting practices.