The study empirically examines the effects of socio-economic (human capital), macroeconomic (per capita GDP), demographic (fertility rate, urbanization), and environmental variables (carbon emissions) on child mortality in South Asia. For empirical analysis, panel cointegration technique is used by using data for five South Asian countries for the period 1973 to 2015. First, it is found that the variables have unit roots at levels but are stationary at first differences, which indicates the possibility of cointegration. Cointegration test results show that long-run cointegrating relationship holds among variables. Fully Modified OLS (FMOLS) and Dynamic OLS (DOLS) methods are applied to find the parameter estimates. The results of long-run estimates show that human capital, per capita income, and urbanization reduce child mortality while high fertility rate and environmental degradation increase child mortality in the region. It is also found that trade openness, immunization, food security, and high life expectancy also decrease child mortality and that population density increases child mortality.