National survey data suggest that new mothers have high prevalences of alcohol and illicit drug use. Depression correlates with substance use, and new mothers with postpartum depression may be at high risk for substance use. Understanding postpartum substance use and its relationship to postpartum depression can inform future research and intervention. A literature search was conducted resulting in 12 studies published from 1999-2012 examining postpartum alcohol use, drug use, or combined postpartum depression and substance use. Postpartum alcohol (prevalence range 30.1%-49%) and drug use (4.5%-8.5%) were lower than use among not pregnant, not postpartum women (41.5%-57.5%, 7.6%-10.6%, respectively) but higher than use among pregnant women (5.4%-11.6%, 3.7%-4.3%, respectively). Correlates of postpartum problem drinking were being unemployed, unmarried, and a cigarette smoker. Prevalence of drug use was highest among white new mothers, followed by blacks and Hispanics, but black new mothers appeared at greater risk of drug use. No identified studies examined correlates of postpartum drug use beyond race/ethnicity. Postpartum depressive symptoms were prevalent among postpartum substance users and those with a substance use history (19.7%-46%). The postpartum period is a critical time. Prevalent substance use and the scarcity of studies warrant research to identify means to reduce maternal substance use.