The paper begins with the discussion of a cause-and-effect econometric model describing life expectancy in Poland in three variants: for men, women, and both sexes at the same time. The analysis is preceded by a brief review of research reports on the subject, with a special focus on empirical applications in the context of adequate explanatory variables. The estimation of the parameters was made with the use of a stepwise regression method, while the final version of the model was selected on the basis of a reliable statistical test, the author says. The research shows that the following variables had a statistically significant impact on life expectancy in Poland in the analyzed period (1975-2005): urbanization, the quality of healthcare, human capital, incomes, economic inequalities, social capital, behavioral factors, and the natural environment. However, the relative impact of these factors on life expectancy differed substantially for men and women, Florczak says. In the second part of the article, the author proposes a model breaking down the population by sex and age, with the use of a “top-down modeling strategy.” The parameters of the Gompertz mortality law and a logistic function were estimated for each year, with the entire population divided into coherent age groups. The resulting demographic model makes it possible to draw up forecasts and simulation scenarios taking into account links between the economic and demographic determinants of growth, Florczak says.