In 2015, students from more than 72 countries and economies participated in PISA, an international assessment. Administered every three years by the OECD, PISA measures the skills of 15 year-old students in applying their knowledge of science, reading, and math to real life problems. PISA provides data on the strengths and areas for development in education systems, supports the development of effective policies, and allows for benchmarking country achievements relative to other participating countries. The World Bank has performed in-depth analyses using PISA 2015 data. The analysis provides insight into factors which determine which education policies have led to improvements - and those which should be strengthened, in various systems. This brief includes regional reports for the Europe and Central Asia (ECA) region and the European Union (EU). A summary for each regional report is included. This brief also includes individual analyses for 22 select countries and economies in the ECA region. The brief analyzes education system inequalities, the benefits of preschool attendance, and student factors, among many others, which impact performance.