tThere is an ever-growing emphasis worldwide on increasing access to early childhood care and educationprograms and generating high-quality educational experiences for children, especially those from low-income families. Chile is not an exception in this global trend. Although Chile has significantly expandedearly education coverage for children from low-income backgrounds, there has been little research toassess the effects these programs have had in improving academic outcomes. Responding to this need,this study assesses the impact of Chile’s public early childhood education programs on fourth-gradeacademic achievement (as measured by the country’s national Education Quality Measurement System,SIMCE). Our results indicate that, after controlling for socio-demographic factors potentially associatedwith choosing to participate in an ECCE program or not, ECCE is positively associated with academic gainson all three SIMCE tests: mathematics, reading, and social sciences. Chilean children who participated inpublic ECCE programs scored on average 0.23 Standard Deviations (SD) higher in math, 0.19 SD higher inreading, and 0.19 SD higher in social sciences than children who did not attend an ECCE program beforeentering Kindergarten. However, our findings suggest that not all children benefit equally from attendingECCE. Results show that boys benefit academically significantly more than girls, and that the ECCE effecton academic achievement also differs depending on the Socioeconomic Status (SES) of the families, withchildren from middle-low SES groups benefiting the most.