The under-five mortality rate is one of the most common indicators of socio-economic development and health of a population. The aim of this study is to investigate the determinants of this index in selected Asian countries, focusing on environmental, socio-economic and demographic factors, using the health production function of Smith and Dunnet (1992) and the spatial econometric model for the period 1980-2022. The results of the cointegration test, considering cross-sectional dependence, indicate the existence of a long- runrelationship between the variables of the model. Also, the results confirm the spatial correlation of the selected Asian countries. In all spatial models (SDM,SAC,SAR), the spatial autocorrelation coefficient is positive, indicating the existence of strong spatial spillover effects on mortality. Pollution (environmental factor ) and unemployment (economic factor) significantly increase mortality, and trade (economic), access to electricity (energy poverty) and education spending (social factor) significantly reduce mortality. The results show that with increasing population density (demographic factor), people have easier access to public health services and public health improves. Also, all explanatory variables in the model have spatial spillover effects on mortality. Therefore, .Public health is a dynamic and evolving field that is constantly changing with environmental, social, economic, and demographic influences. Policies to control pollution, reduce unemployment, increase trade, education spending, and access to electricity should be a priority for Asian countries to protect the health of their own communities and neighboring countries. Improving the quality of life and improving public health requires international cooperation