this article presents the results through sixth grade of a longitudinal randomized control study of the effects of a scaled-up, state-supported pre-k program. the analytic sample includes 2,990 children from low-income families who applied to oversubscribed pre-k program sites across the state and were randomly assigned to offers of admission or a wait list control. data through sixth grade from state education records showed that the children randomly assigned to attend pre-k had lower state achievement test scores in third through sixth grades than control children, with the strongest negative effects in sixth grade. a negative effect was also found for disciplinary infractions, attendance, and receipt of special education services, with null effects on retention