The evolution of mortality is one of the main components of population dynamics. The health status of a population is therefore a key factor in the evolution of mortality and the demographic dynamics of a country. The evolution of mortality and its corollary, the health of populations, as well as the disparities observed between developed and developing countries – and even within different regions and continents – are much less subject to interpretation than in the case of other phenomena and are more factual. This chapter analyzes these aspects on the basis of the data provided by the World Health Organization and the United Nations, as part of the monitoring of Millennium Development Goals and Sustainable Development Goals. The mortality of children and women is still disproportionately high in developing countries. The large number of premature deaths is a worrying public health problem, especially affecting children under five and women of childbearing potential.