Objective: Fear of jeopardizing drinking outcomes has resulted in a reluctance to treat tobacco dependence concurrently with alcohol dependence, in spite of the high prevalence of smoking among patients with alcohol dependence. The objective of this study was to compare the effects of smoking treatment and intensive treatment for alcohol dependence, delivered concurrently, with delayed smoking treatment on smoking and alcohol use. Method: For the study, 1,943 patients in intensive treatment for alcohol dependence or abuse were screened for participation. Of these, 499 smokers were enrolled and randomized to concurrent (during alcohol treatment) or delayed (6 months later) smoking intervention. The smoking intervention included individual behavioral counseling and nicotine replacement. The main smoking outcome measure was 7-day point prevalent tobacco abstinence, and the main drinking outcome was 6-month prolonged abstinence from alcohol; both measured 18 months after study enrollment. Results: Participants in the concurrent group were more likely to participate in smoking treatment than those in the delayed group (78.5% vs 64.5%, p = .005), but there was no significant difference in cessation rates at 18 months (12.4% vs 13.7%). Prolonged, 6-month abstinence from alcohol was worse in the concurrent group than in the delayed group at 6, 12 and 18 months (41% vs 56%, p = .001; 33% vs 42%, p = .06; 41% vs 48%, p = . 14, respectively), and 30-day prolonged alcohol abstinence was also worse in the concurrent treatment group (51 % vs 64%, p = .004; 46% vs 53%, p = .11; 48% vs 60%, p = .01, respectively). Conclusions: These data show that patients in alcohol treatment are interested in smoking cessation, participate in treatment and demonstrate success; but there was no benefit of concurrent treatment. Drinking outcomes were worse with concurrent tobacco treatment. These findings suggest that smoking cessation intervention should be provided to patients after intensive alcohol treatment; however, the data require confirmation because they are not consistent with the existing literature.