The authors investigated whether age at kindergarten entry was associated with early literacy achievement gaps and if these gaps persisted over time. Using the kindergarten age eligibility cutoff date, they created 2 groups of students who represented the oldest and youngest children in a cohort of students in high-poverty, low-performing schools. The authors followed 405 students from the beginning of kindergarten until the end of Grade 2. Results indicated that the youngest students scored lower than their oldest peers at the beginning of kindergarten on various early literacy measures. The early-age achievement gap, however, narrowed over time but did not close completely by the end of Grade 2. Implications for parents and educators are discussed. (Contains 2 notes, 5 tables, and 1 figure.)