Although parental involvement in children's literacy development has been recognized for its potential in helping children develop early literacy achievement, studies of the effectiveness and sustainability of school-based parent involvement programs are not numerous. This study examines the effectiveness and durability of a school-based parent involvement program that was implemented by school staff without external supervision over 3 consecutive years in a public school. Results indicate that implementation of the program was associated with higher levels of children's achievement in foundational literacy competencies. Moreover, the program has sustained over 3 years and actually grew in the levels of parental participation over time. The authors argue that effective and systemic parental involvement programs are possible and can be guided by certain principles of program development and if implemented by a committed teaching staff.