In practice, Leaving No One Behind means moving beyond assessing average and aggregate progress, towards ensuring progress for all population groups at a disaggregated level. This requires disaggregating data to identify groups being excluded or discriminated against, as well those experiencing multiple and intersecting forms of discrimination and inequalities.The methodological tool presented in this paper (Classification and Regression Tree (CART) Analysis) uses the Demographic and Health Surveys (DHS) and the Multiple Indicator Cluster Surveys (MICS). DHS and MICS are publicly available for 30 Asian and Pacific countries and 15 countries in Latin America and the Caribbean in the FEALAC region.