Racial and social class differences in rates of preterm birth and other adverse outcomes are among the most widely recognized and least well-understood phenomena in the study of reproductive health. Individual-level characteristics have failed to account for such gradients. Recently, researchers have begun to argue that health in general and reproductive outcomes specifically are rooted in social inequalities. One area of such inequality may be residential segregation and the associated race/ethnic differences in exposure to adverse neighborhood conditions. We review the empiric data that examine the association between neighborhood conditions and reproductive health. We also review the major challenges that researchers face when trying to incorporate neighborhood-level variables into studies of health outcomes. Our goal is to stimulate further research that simultaneously considers social, economic, and biologic determinants of reproductive health.