Carrilero N, et al. - This study sought to assess socioeconomic and gender inequalities in the pre-COVID-19 era for 29 diseases in the entire childhood population in Catalonia to identify which diseases are most impacted by inequalities. Researchers designed a population-based study including 1,449,816 children under 15 years old from 2014 to 2017 and each of their registered diagnoses within the Catalonia National Health System. Four regression-based inequality measures were calculated: slope index of inequality, relative index of inequality, absolute population-attributable fraction, and population-attributable fraction. The findings revealed that socioeconomic and gender inequalities are widely present in childhood health. Although it varies in magnitude according to each disease, this demonstrates that SES plays a common role in their development. In addition, action requires to be taken to ensure a fairer start in life in terms of health.