The economic theory of fertility postulates that income and prices, broadly defined, are important determinants of family size. What follows is an attempt to test this theory against the behavior of 717 predominantly urban households in Sierra Leone. Husband’s education is used as a proxy for income; the “price” of a child is accounted for by wife’s education and wife’s wage rate. Other important variables are wife’s age, a measure of child “quality,” wife’s age at first birth, and child mortality. The findings of the study tend to lend support to the economic theory of fertility but contain certain peculiarities which indicate a need for further research.