Substance abuse in pregnancy places both mother and infant at extremely high risk. There is little information, however, about the impact of changing patterns of drug use and improvements in medical technology on pregnancy outcome. The Family Center Program utilizes a team approach to provide counseling, support, and education as well as complete medical care for substance-abusing pregnant women. We reviewed the records of women seen in the Family Center Program from 1981 to 1983 to evaluate the effect of intervention on pregnancy outcome. Complications, including prematurity, growth retardation, intrauterine fetal demise, and neonatal abstinence, were common, although early prenatal care and frequent visits appear to reduce the risk of low birth weight infants. Uncorrected perinatal mortality was 11/163 (67/1,000). Compared to earlier experience in this program, few women delivered with no prenatal care. Thus a program designed specifically for the needs of these women is successful in increasing the number seeking prenatal care and appears to improve pregnancy outcome. Despite this, serious problems are common and further improvement seems unlikely unless such women can be maintained in a stable, drug-free environment during their pregnancies.