The authors of this article examine the relationship between social factors and low birth weight and the ways in which disparities in socioeconomic status have been addressed over time. The evidence regarding the effectiveness of various efforts to influence birth weight by mitigating the consequences of disadvantage are also assessed. Low socioeconomic status has been shown to influence low birth weight through its various correlates. Historically and today, most programs and policies directed at low birth weight prevention attempt to address the individual health consequences of economic and social disadvantage. By and large, these efforts have produced mixed results. Efforts to affect low birth weight by addressing the underlying causes of social and economic disadvantage have been similarly inconclusive, reflecting the paucity of research on the subject, as well as the historical and ongoing failure to make the research link between health and social policy. The authors argue that reducing persistent disparities in low birth weight requires several steps, including embracing a broader definition of health which incorporates social dimensions, recasting the focus of research and interventions from pregnancy outcomes and infant health exclusively to include the notion of women's health more globally, expanding the research agenda to unravel the paradox of socioeconomic factors and health, and pursuing a dedicated, national commitment to assuring adequate support to individuals and families, including both adequate income and health care.