Social and economic structural characteristics of counties are used to predict differences in county fertility rates using 1970 census data for North Carolina's one hundred counties. We argue that fertility rates are affected by county social and economic structures, and hypothesize that fertility rates vary directly with level of occupational sex segregation and inversely with degree of urbanization, industrialization, population size, and female labor force participation rates of counties. Variables reflecting general sociodemographic characteristics of counties are also included in the analysis. Using multiple linear regression and factor analytic techniques, a preliminary model of social and economic structural antecedents of fertility is constructed. Three factors, which collectively account for 69 percent of the variance in fertility rates, are indicative of the importance of social and economic structural conditions in accounting for variation in local fertility.