The female prison population has increased dramatically in recent years. Most women inmates are involved with drugs, and as many as 25 percent are pregnant or have delivered within the past year. Reproductive health and drug treatment services for women in prison are inadequate, if they exist at all, and although illicit drugs are readily available in prison, drug-involved pregnant women are often incarcerated to protect fetal health. Studies of pregnancy outcomes among women prisoners have shown high rates of perinatal mortality and morbidity. Women and Infants at Risk (WIAR) is a comprehensive residential program for pregnant, drug-dependent women in the Michigan State adult corrections system. Its goals are to increase the availability of substance abuse prevention and treatment services to pregnant and postpartum women offenders, to reduce the severity and effect of drug exposure to the infants, to reduce the likelihood of relapse and recidivism among the mothers, and to promote community awareness of the needs of pregnant prisoners and their infants, as well as facilitate coordination among relevant State and local agencies to improve services to them. WIAR was developed by social work students who organized a coalition of health and human services agencies, State and local government officials, and administrators from the State Department of Corrections agencies to investigate and address the needs of incarcerated pregnant women. This article describes the program's needs assessment, eligibility criteria and program entry, intensive prenatal care, substance abuse treatment and life skills training, and pregnancy outcomes among program participants. Birth outcomes among participants in WIAR were clearly better than those of the women inmates surveyed in the original needs assessment. 36 references