CIES 2018 Presentation, given by Tara Weatherholt. A current challenge in the equitable access to quality pre-primary education for young children is the current lack of relevant and reliable data on pre-primary education to inform improvement of the education sector in developing country contexts. In 2015, the global Measuring Early Learning and Quality Outcomes (MELQO) initiative was formed by UNICEF, UNESCO, the World Bank, and the Brookings Institution to focus on facilitating feasible, accurate, and useful measurement of young pupils’ development at the start of primary school as well as the quality of pre-primary learning environments, particularly in low- and middle-income countries. The first nationally representative school readiness study utilizing the MELQO suite of instruments was recently completed in Tanzania. This presentation will report on the quality of pre-primary education environments in both Mainland Tanzania and Zanzibar, as found through the national MELQO study conducted in early 2017, and how this may inform sector improvement.