A growing body of evidence has found that Early Childhood Education (ECE) gives longer-term beneficial effects on a student's cognitive ability. Unfortunately, in developing countries, and especially other low-resource environments, too few children have the privilege to attend ECE. Using INOVASI's 1 large-scale longitudinal datasets, this study presents the inequality issue of ECE participation and its effect on students' learning outcomes in Indonesia. The findings suggest that participation rates in ECE are significantly higher in more developed provinces in Indonesia. ECE is mainly dominated by students from higher socio-economic backgrounds, and those with more well-educated and engaged parents. ECE participation rates also have an impact on student learning achievement, with children participating in ECE having substantially better outcomes compared to their counterparts. Furthermore, students who did not enroll in ECE may lose almost two years of learning. The evidence puts forth in this paper suggests that the Indonesian government needs to improve access to ECE and its quality particularly for less advantaged children in remote areas. Inattention to this issue will only produce wider inequality in education and learning outcomes.