Substance abuse poses significant health risks to reproductive age women in the United States and, for those who become pregnant, to their children. Substance abuse or dependence is defined as a maladaptive pattern of substance use marked by recurrent and significant negative consequences related to the repeated use of substances. Alcohol is the most prevalent substance consumed by childbearing-aged women, followed by tobacco and various illicit drugs. Substance use in the preconception period predicts continued but often limited substance use during the prenatal period. Providers must be aware of reproductive age women's unique physiologic, psychological, and social needs and the related legal and ethical ramifications surrounding substance abuse before referral to a community-based multidisciplinary team for often long-term treatment.