This brief provides an overview of the Blue Box, a tool that involves parents and caregivers to prevent or mitigate developmental delay of children ages 2 months to 3 years through the act of play. Specifically, it targets children with impairments, premature children, low birth-weight children with malnutrition, and children living with social and psychological distress. The Blue Box includes activity cards, flip charts, a developmental journal, and a toy box.