This paper provides an overview of epidemiological and demographic research linking social characteristics of both individuals and communities to differences in both morbidity and mortality risks. Evidence is presented linking three broad aspects of the social environment to health--the network of personal social relationships within which most of us live our lives, individual socioeconomic status (SES), and community-level social characteristics. Large and consistent bodies of literature from both epidemiology and demography provide clear evidence for the generally health-promoting effects of personal social relationships and SES. The bulk of the evidence relates to mortality although both fields have begun to examine other health outcomes, including aspects of physical and cognitive functioning as well as disease outcomes. A smaller but growing body of community-level data, reflecting both the socioeconomic/resource characteristics of these broader communities and, more specifically, social features of these environments, also point to health impacts from these more macro level social environment characteristics. Much remains to be elucidated, however, concerning the actual mechanisms through which something as complex and multifaceted as SES "gets under the skin." This necessarily includes consideration of external characteristics of the environments (both physical and sociocultural) where people live and work, and individual characteristics, as well as possible interactions between these in producing the observed SES gradients in health and mortality. These questions concerning links between social environment conditions and health may be a particularly fruitful area of future collaboration, drawing on the shared interest of demographers and epidemiologists in understanding how different social conditions promote variation in distributions of better versus worse health outcomes within a population.