Context: National and state efforts to increase folic acid awareness and use may not be reaching large segments of the population. Purpose: This study examines folic acid awareness and use among women of childbearing age in a representative, economically at-risk rural sample and identifies factors that influence awareness and use. Methods: A cross-sectional random digit dialing telephone survey was completed with a representative sample of 646 women aged 14-45 years in 36 counties of the lower Mississippi Delta. Folic acid awareness and supplement use were estimated by percentages weighted to reflect the 36-county population. Pregnancy intentions and the ability to become pregnant were used to predict awareness and use among a subsample of sexually active women. Findings: Compared to national samples, Delta women were less likely to have heard of folic acid (75% vs 64%) or to take a regular (5-7 days/wk) folic acid supplement (34% vs 22%). The proportion of women who took regular folic acid supplements was very low among some subgroups: African Americans (14%), those 14-19 years of age (12%), and those with low incomes (13%) and low educational levels (14%). Of the women who reported being sexually active, the ability to become pregnant more than doubled their likelihood of regular supplement use. Conclusions: The national folic acid campaign has not reached many women in the rural Mississippi Delta. A new mode of folic acid education is needed that is focused on low-income and young women and women not planning pregnancies. In the Delta and similar geographic regions, health care providers, black church leaders, and youth group leaders could be valuable advocates for folic acid.