Fetal alcohol syndrome (FAS) is caused by heavy alcohol consumption during pregnancy and is characterized by specific anomalies of the face; prenatal and postnatal growth deficits; and a variety of central nervous system (CNS) abnormalities, including mental retardation. Children with either full or partial FAS often incur severe and costly secondary disabilities. Despite the importance of surveillance for establishing the magnitude of FAS and in monitoring trends in the occurrence of this disease, population-based surveillance for FAS has been difficult because the syndrome can be diagnosed only by clinical observation and often is not recognized until after the child reaches school age. Although most FAS surveillance has been based on diagnoses among newborns, most (89%) cases (full FAS and partial FAS) are diagnosed after the age of 6 years. To develop a more accurate estimate of the prevalence of FAS in a defined population, in 1997 CDC linked data from the Metropolitan Atlanta Congenital Defects Program (MACDP) and the Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) for children born in Atlanta during 1981-1989 (the most recent birth year for which data were available for 3-10-year-olds). This report presents a multiple-source method for FAS surveillance that is more complete than previous methods and that enables comparison of rates between states.