Opioid dependence during pregnancy is associated with significant health risks for both the mother and her fetus. Opioid maintenance therapy with methadone (Dolophine) is the current standard of care, reduces medical and social risks associated with illicit drug use, and decreases rates of prematurity and low birth weight. However, treatment with methadone is frequently associated with neonatal abstinence syndrome. Buprenorphine is an alternative to methadone that preliminary data indicates is equivalent in safety and efficacy to methadone and significantly increases access to treatment. The pharmacology of buprenorphine and its implications for the care of pregnant women with opioid dependence are described.