The National Drug Abuse Treatment Clinical Trials Network (CTN) recently completed a randomized, open label trial comparing treatment as usual (TAU) combined with nicotine patches plus cognitive behavioral group counseling for smoking cessation (n = 153) to TAU alone (n = 72) for patients enrolled in treatment programs for drug or alcohol dependence, who were interested in quitting smoking. This report is a secondary analysis evaluating the effect of depressive symptomatology (n = 70) or history of depression (n = 110) on smoking cessation outcomes. A significant association was seen between measures of depression and difficulty quitting cigarettes. Specifically, there was a greater probability for smoking abstinence for those with lower baseline Beck Depression Inventory II (BDI-II) scores. These data suggest that evaluation and treatment of depressive symptoms may play an important role in improving smoking cessation outcomes. (Am J Addict 2010;00:1-8).