This study analyzed the effect of Early Childhood Education on Academic Achievement in Indonesia. This study used kindergarten education and National Test Score of Indonesian Language and Math as the main subject of research. This study obtained the sample from Indonesian Family Life Survey (IFLS) 2007. The econometric method, that this study used, was Ordinary Least Square (OLS). This study presented the estimation based on school level, primary and secondary. This study founded that kindergarten education (formal Early Childhood Education) affected National Test Score of Indonesian Language and Math significantly if other factors did not add in the regression. This finding caused the effect of kindergarten education to National Test Score became not valid or biased. The problems like high cost of early childhood education and lack of teacher could be the reason why the effect of early childhood education was not maximal. This problems can be the the next subject of research about early childhood education.