Aims-The prospect of weight gain discourages many cigarette smokers from quitting. Practice guidelines offer varied advice about managing weight gain after quitting smoking, but no systematic review and meta-analysis have been available. We reviewed evidence to determine whether behavioral weight control intervention compromises smoking cessation attempts, and if it offers an effective way to reduce post-cessation weight gain.Methods-We identified randomized controlled trials that compared combined smoking treatment and behavioral weight control to smoking treatment alone for adult smokers. Englishlanguage studies were identified through searches of PubMed, Ovid MEDLINE, CINAHL, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials. Of 779 articles identified and 35 potentially relevant RCTs screened, 10 met criteria and were included in the meta-analysis.Results-Patients who received both smoking treatment and weight treatment showed increased abstinence (OR=1.29, 95% CI=1.01,1.64) and reduced weight gain (g = -0.30, 95% CI=-0.63, -0.04) in the short term (<3 months) compared with patients who received smoking treatment alone. Differences in abstinence (OR=1.23, 95% CI=0.85, 1.79) and weight control (g= -0.17, 95% CI=-0.42, 0.07) were no longer significant in the long term (>6 months).Conclusions-Findings provide no evidence that combining smoking treatment and behavioral weight control produces any harm and significant evidence of short-term benefit for both abstinence and weight control. However, the absence of long-term enhancement of either smoking cessation or weight control by the time-limited interventions studied to date provides insufficient basis to recommend societal expenditures on weight gain prevention treatment for patients who are quitting smoking.