To study the influence of health care systems on racial differences in low birthweight and neonatal mortality, an historical cohort analysis was conducted using birth and linked birth and death certificates of infants delivered in Pierce County, Washington, between 1982 and 1985. Overall, black infants had significantly higher rates of low birthweight than white infants. Black infants served by civilian medical care had approximately twice the neonatal mortality of white infants; however, black infants born in the military hospital had a neonatal mortality rate comparable to white infants. Controlling for marital status, age, parity, and income status did not appreciably change these patterns. Military care appeared to be associated with a protective effect for neonatal mortality for blacks. This effect was not due to differences in birthweight distribution or to the quantity of prenatal care received. The effect was most prominent for normal weight black infants, especially for those from low-income census tracts. The findings have possible implications for pediatric access issues for the poor and for the family practice model of perinatal care continuity.