Epidemiologists cannot afford to ignore poverty. To do so would, first, wrongly obscure the devastating impact of poverty on population health, and, second, undercut our commitment to scientific rigor. At issue is doing correct science, not "politically correct" science. Blot poverty and inequity from view, and not only will we contribute to making suffering invisible but our understanding of disease etiology and distribution will be marred. To make this case, I address current debates about the causal relationships between poverty and health, and provide examples of how failing to consider the impact of socioeconomic position has biased epidemiologic knowledge and harmed the public's health. By definition, the people we study are simultaneously social beings and biologic organisms-and we cannot study the latter without taking into account the former. It is the responsibility of all epidemiologists, and not only social epidemiologists, to keep in mind the connections between poverty and health.