Adequate prenatal care is known to reduce the risks of low birth weight and neonatal death, yet nearly one quarter of all women giving birth in the United States receive delayed, inadequate or no prenatal care. This suboptimal use of prenatal care has contributed to rates of low birth weight and neonatal mortality higher than those in most other industrialized nations. This paper examines the relationships among race/ethnicity, residence, maternal sociodemographic and medical risk characteristics, and use of prenatal care in the United States. Using data from the National Maternal and Infant Health Survey, this study found important differences in prenatal care use by race/ethnicity and residence, as well as interactive effects of these variables. Single marital status, nonmetropolitan residence, poverty, low level of education, and no insurance were more strongly associated with inadequate prenatal care for whites and Hispanics than for blacks. Nonmetropolitan residents were more likely to receive inadequate care, regardless of race/ethnicity or sociodemographic characteristics. Predicted probabilities of prenatal care use by race/ethnicity and residence showed that, regardless of risk, nonmetropolitan Hispanic women had the highest probability of obtaining inadequate prenatal care. Results highlight the continued importance of race/ethnicity and rural residence in determining prenatal care use and the need to design interventions targeted to these populations.