Victora CG, Barros AJD, Blumenberg C, et al. - This study investigated the relationship between ethnicity and under-5 mortality. Researchers included data from 36 low-income and middle-income countries (LMICs) involving a total of 2,812,381 live births among 415 ethnic groups. Data were applied from Demographic and Health Surveys and Multiple Indicator Cluster Surveys collected between 2010 and 2016, from LMICs that presented birth histories and information on ethnicity or a proxy variable. The neonatal (age 0–27 days), post-neonatal (age 28–364 days), child (age 1–4 years), and under-5 mortality rates (U5MRs) were measured for each ethnic group within each country. They further estimated differences in mortality between ethnic groups using a likelihood ratio test, Theil's index, and between-group variance. The multivariable analyses of U5MR was applied by ethnicity to adjust for household wealth, maternal education, and urban-rural residence. The study found significant ethnic disparities in child survival in more than two-thirds of the countries studied. Regular analyses of ethnic disparities are necessary for monitoring trends, targeting, and evaluating the effect of health interventions. It was demonstrated that such reports will contribute to the effort towards leaving no one behind, which is at the centre of the SDGs.