Despite substantial reductions in U.S. infant mortality during the past several decades, black-white disparities in infant mortality persist. Among 40 states with sufficient numbers of black infant deaths to generate reliable rates for the years 2002-2004, Wisconsin had the highest black infant mortality rate (IMR) at 17.6 deaths per 1,000 live births, approximately three times the state rate for whites. However, in contrast to trends in Wisconsin and the other 39 states, the black IMR in Dane County, Wisconsin, has declined substantially, achieving parity with whites and meeting Healthy People 2010 objective 16-1 for reducing fetal and infant deaths. The county rate declined 67%, from 19.4 per 1,000 live births for the period 1990-2001 to 6.4 for the period 2002-2007. To gain understanding of this development, Public Health Madison Dane County (PHMDC) analyzed approximately 100,000 birth and death records from 1990 through 2007 for birthweight, gestational age, prenatal care, and other infant mortality risk factors. The main contributors to the decrease in black infant mortality were a large decrease in the extremely premature (<or=28 weeks gestation) birth rate and a decrease in the mortality rate for newborns weighing <1,500 g. Because the observed trend in black infant mortality is based on small reductions in the absolute number of deaths (approximately three infants per year), conclusions based on these results should be considered preliminary, and additional studies are needed to confirm the reduction in rates over time. PHMDC is planning continued surveillance and other studies to determine whether the reduction in mortality is stable.