Abstract: In this paper we attempt to uncover the complex relationship that exists between fertility and female labor force participation in low- to middle-income countries. Using the Demographic and Health Surveys, we illustrate the heterogeneity in the relationship across and within countries. Sub-Saharan African countries have high rates of fertility and high labor force participation. Within countries, women in sub-Saharan Africa are much less responsive in their labor supply to an increase in fertility than women in other continents. Across all countries, women who have lesser education or live in rural areas are much less responsive in their labor supply decision in the event of an extra child than women who are more highly educated or live in urban areas. The type of work women do also determines how responsive they are in their labor supply decision in the event of an extra child. Women who have strong workplace attachment are more likely to discontinue working in the event of a child than women who work in more flexible environments where work and childcare may be conducted simultaneously. We illustrate our attempts to identify a causal relationship between fertility and female labor force participation. We also discuss the limitations of using the Demographic and Health Survey’s measure of female labor force participation.