There are differences in fertility levels between countries, and it is known according to the literature that there are several factors on which the fertility rate depends. The main goal of this thesis is to investigate the relationship between the level of fertility, national income and women's education. For this purpose, data for 168 countries for the year 2019 was used. The data comprised the total fertility rate, gross national income per capita, mean years of schooling of women, women's labor force participation and infant mortality. All data was taken from the official websites of the World Bank and Human Development Reports. An analysis was performed that started with simple descriptive statistics, following which several regression models were estimated. The first two models examined the relationship between fertility and national income and women's education individually. In the third model, national income and women's education were included together. In the next step, infant mortality and women's labor force participation were added to the model. Finally, the interaction between national income and women's education was examined. In line with the expectations, the results showed a negative relationship between fertility and income, as well as between fertility and women's education. By introducing women's education into the regression model with income, the negative relationship between income and fertility weakened and income became statistically insignificant. The link between fertility and income was further weakened by the introduction of other variables. This suggests that the negative relationship between fertility and income is a reflection of other factors that correlate with income. Also, a significant interaction was found between income and women's education in the effect on fertility, from which it is evident that the relationship between fertility and women's education is weaker in countries with higher income.