The objective of this study was to examine socioeconomic (SES) gradients in infant health across a number of racial and ethnic groups in the United States. The study was based on data from a new nationally representative sample of children born in the US in 2001 (N = 8,650). The data include oversamples of several minority groups and a rich set of socioeconomic indicators, as well as demographic, health, and health behavior characteristics. Proportion of low birth weight (LBW) and small for gestational age (SGA) (and 95% CIs) across categories of several indicators of SES (maternal education, income, income adjusted for family size, and wealth) was presented for the full sample of children and disaggregated by race/ethnicity: non-Hispanic white, non-Hispanic black, Hispanic, Asian/Pacific Islander (A/PI), and American Indian/Alaskan Native (AI/AN). A graded relationship was found between all measures of SES and infant health for white mothers, and between adjusted income and LBW for Asian and Hispanic mothers. There was no relationship between any indicator of SES and either LBW or SGA for either black or AI/AN mothers. The finding that some minority racial/ethnic groups do not reap the same health benefits from higher levels of SES as do whites suggests that approaches to reducing health disparities must address not only the structural barriers that lead some minority groups to have fewer resources but also barriers that prevent these groups from taking advantage of those resources to improve the health of their families.