This viewpoint examines girls' performance in primary education in the countries that joined the Education for All Fast Track Initiative between 2002 and 2008. At the time they joined the initiative, a first group of countries (high performers) had already achieved high and equal enrollment of girls and boys. Significant progress is evident in a second group of countries (good performers) after joining the initiative. In contrast, a third group of countries (weak performers) continue to struggle to achieve any increase in girls' enrollment. The article summarizes the various interventions that countries have adopted to encourage girls to attend school and then highlights the importance of developing strategic plans based on extensive collaboration between development partners and government. The viewpoint concludes by describing the three challenges that remain: increasing learning, reducing the number of out-of-school girls, and improving girls' performance in fragile and post-conflict countries.