Signs of development delays and malnutrition are widespread among young children in low-income settings. Social protection programs such as cash transfers are increasingly combined with behavioral change promotion or parenting interventions to improve early childhood development. This paper disentangles the effects of behavioral change promotion from cash transfers to poor households through an experiment embedded in a government program in Niger. The study is also designed to identify within-community spillovers from the behavioral change intervention. The findings show that behavioral change promotion affects a range of practices related to nutrition, health, stimulation, and child protection. Moderate gains in children's socio-emotional development are observed, but there is no improvement in anthropometrics or cognitive development. Cash transfers alone do not alter parenting practices or improve early childhood development. Cash transfers raise food security and consumption at the household level, including the purchase of non-food items privately consumed by adults. The behavioral intervention offsets these changes and instead improves children's food security, pointing to some intra-household reallocations toward children. Local spillovers on parenting practices are found, which further highlights that cash alone is not the main driver of changes in parenting behaviors.