This study investigates the association between cigarette use and current mood/anxiety disorders among pregnant opioid-dependent patients. Pregnant methadone-maintained women (N = 122) completed the Addiction Severity Index and Structured Clinical Interview for DSM-IV. Participants were categorized based on past 30 days cigarette use: no (n = 15) and any smoking (n = 107); this latter group was then subdivided into light (one to ten cigarettes/day; n = 55), and heavy smokers (11+ cigarettes/day; n = 52). Any smoking was significantly associated with any current mood/anxiety disorder (p < 0.001), any current mood disorder (p = 0.007), and any current anxiety disorder (p < 0.001). No significant association was found between specific level of cigarette use and mood/anxiety disorders. This association between smoking and psychiatric disorders has implications for the mental and physical health of methadone-maintained women and their children, and may contribute to the understanding of the physiological mechanisms underlying smoking and nicotine dependence.