Despite the strong argument for investing in young children and the many types of interventions and delivery mechanisms that have been developed, knowledge on Early Childhood Development (ECD) programs' effectiveness in low-income settings remains thin. Yet a growing number of programs in developing countries contain interventions seeking to improve ECD outcomes by changing parenting practices. Large signs of cognitive delays have been document among children in rural Nicaragua, therefore, this study was conducted in six rural municipalities with high levels of extreme poverty to test the impact of a home-visiting parenting intervention on early childhood development outcomes in a low-income setting, as well as the relative effectiveness of targeting the intervention to mother or mothers and fathers. Results indicate that the preliminary analysis suggests small but significant improvements in ECD indicators from the home-vising intervention in targeted communities. Significant impacts are documented on cognitive development, motor skills and socio-emotional development. Impacts were found to be larger for the treatment modality involving mothers and fathers, and relatively larger for boys. Also the potential for interventions to change parental practices, attitudes, and targeting fathers can have large pay-offs.