Fetal alcohol syndrome (FAS) is caused by maternal alcohol use during pregnancy and is one of the leading causes of preventable birth defects and developmental disabilities in the United States. FAS is diagnosed on the basis of a combination of growth deficiency (pre- or postnatal), central nervous system (CNS) dysfunction, facial dysmorphology, and maternal alcohol use during pregnancy. Estimates of the prevalence of FAS vary from 0.2 to 1.0 per 1,000 live-born infants. This variation is due, in part, to the small size of the populations studied, varying case definitions, and different surveillance methods. In addition, differences have been noted among racial/ethnic populations. To monitor the occurrence of FAS, CDC collaborated with five states (Alaska, Arizona, Colorado, New York, and Wisconsin*) to develop the Fetal Alcohol Syndrome Surveillance Network (FASSNet). This report summarizes the results of an analysis of FASSNet data on children born during 1995-1997, which indicate that FAS rates in Alaska, Arizona, Colorado, and New York ranged from 0.3 to 1.5 per 1,000 live-born infants and were highest for black and American Indian/Alaska Native populations. This study demonstrates that FASSNet is a useful tool that enables health care professionals to monitor the occurrence of FAS and to evaluate the impact of prevention, education, and intervention efforts.