Based on the Head Start Impact Study (HSIS) data, the current study examines Head Start’s long-term impacts on cognitive outcomes for children with disabilities: (a) Do children with disabilities who enroll in Head Start at age 4 years have better cognitive outcomes when they are 4 to 9 years old? (b) Are there other factors associated with long-term cognitive development for children with disabilities? Linear regression analysis indicated that Head Start enrollment had positive impacts on children’s short-term outcomes. However, the difference between Head Start and non-Head Start children became insignificant for cognitive scores measured at age 9 years. Children who were Black or Hispanic, without an individualized education plan, were non-English speaking at home, and who had lower preacademic skills prior to Head Start enrollment had significantly lower cognitive outcomes at age 9 years.