This report takes stock of educational underachievement among boys and men, examines the evidence on contributing factors, and explores what has been done to address the phenomenon. While female underrepresentation in secondary and tertiary education remain a significant issue in some, particularly low-income, countries, more than 100 countries have lower levels of male secondary and tertiary education enrollment and completion. Learning poverty rates-the proportion of children unable to read and understand a simple text at 10 years of age-are higher for boys than for girls in all regions and almost all countries of the world. Across various grades and subjects, in many countries boys tend to have poorer learning outcomes than girls, with substantial differences in some countries, particularly in the Middle East and North Africa (MENA) region, as regularly demonstrated in international assessments of student learning. For high-income countries, this is not a new development-it has been readily acknowledged and discussed in the literature since the 1990s. What has become increasingly common is the observance of this gap in middle-income countries as well.