This study examines whether a large expansion of pre-primary education in Ethiopia affected subsequent students’ learning outcomes during the national reform of pre-primary education. The study utilizes two comparable, representative early grade reading assessment data that straddle the reform period from 2010 to 2016, during which enrolment rates in pre-primary education soared by nearly ten times nationwide. We find that associations between preschool participation and literacy outcomes were positive and significant after the expansion, yet no such relationships were observed before the reform. However, there was little heterogeneity in the gains of the preschool participation by gender, urbanity, and parental literacy. We discuss implications for ongoing reform, including strategic and inclusive policy designed to close the learning gap between children from advantaged and disadvantaged backgrounds.