Education system data has indicated a pattern of over-enrollment in the early grades in some low-income countries. One factor that may influence the observed enrollment bulge is access to pre-primary education programs, as children who do not enter school prepared could be more likely to repeat leading to more children enrolled than are of enrollment-age. This presentation reports on a research study undertaken in Uganda to better understand pupil enrollment and repetition in Primary 1 as it relates to pre-primary access. Data was collected from schools in a district with high reported repetition, lack of or low preprimary access, and high apparent dropout between grade 1 and 2, and a district with low reported repetition, high preprimary access, and low apparent grade 1 dropout. School records were reviewed to collect ages of enrolled pupils and repeater status, in order to calculate age patterns and repetition rates in Primary 1 for each district. In addition, parents of randomly sampled pupils were interviewed about their child’s preprimary attendance, repetition of primary one or other grades, and access to preprimary education programs. Teachers of the sampled pupils were also interviewed regarding pupil age and repetition history. Overall, data was collected on 1,909 pupils in 80 schools, and 1,792 parents were interviewed. The presentation will focus on the following research questions: 1) What are the estimated repetition rates as reported by parents and schools in Primary 1 in schools in the sampled low- and high-risk districts in Uganda; 2) What are the ages of the pupils attending Primary 1 in our sample of Uganda schools and how does this relate to repetition; 3) How do the reported repetition rates relate to parent report of ECD attendance and access; and 4) What is the discrepancy between school-reported and parent-reported repetition rates. Data collection methods, measurement of repetition and ECD attendance and access, and policy conclusions will also be discussed.