This study investigates the determinants of fertility in the long run, using a newly constructed panel data set consisting of fertility rates, measured as crude birth rates, infant mortality rates, per-capita income, and the educational attainment of men and women for 43 countries from 1890 to 2010 at five-year intervals. The regression results show the significant effects of per-capita income, infant mortality, educational attainment, and political development on fertility rates. A woman’s educational attainment at the primary and secondary levels has a pronounced negative effect on fertility rates. On the contrary, an increase in a woman’s tertiary educational attainment, with the level of a man’s remaining constant, tends to raise fertility rates, indicating that highly educated women can have a better environment for childbearing and childrearing in a society with greater gender equality. The presented research thus identifies the important role of human capital accumulation, especially attained by women, in demographic transition through fertility decisions for over a century of human history.