Mindfulness is a skill of intentionally directing one's attention to emotions, thoughts, or physical sensations with an open-minded, non-judgmental attitude. Mindfulness can enable a person to experience challenging feelings or situations without reacting impulsively or automatically. Mindfulness training may be provided to smokers to help them manage smoking triggers, urges, stress, or negative emotions without smoking. Randomized controlled trials have now shown that mindfulness training for smokers (MTS) yields smoking abstinence rates that are equal to or higher than matched behavioral treatments. We describe a comparative observational study on MTS within an ongoing clinical program. The study was conducted with a naturalistic design and utilized no procedures or evaluations beyond those already employed in clinical practice. All participants were advised to use FDA-approved smoking cessation medications and were provided with a choice of two behavioral treatments-MTS (selfpay) or the Wisconsin Tobacco Quit Line (WTQL) (free). Over a 12-month study period, 181 clinic patients enrolled; 65.75% (119) choose MTS and 34.25% (62) choose WTQL. MTS compared to WTQL treatment initiators showed significantly higher biochemically confirmed 7-day point prevalence smoking abstinence at 2 weeks postquit attempt (MTS = 47.00%, QL = 24.52%, p = .011, OR = 2.71). Intent-to-treat analysis showed similar outcomes (p = .019, OR = 2.45). The study provides evidence that MTS provided within clinical program leads to similar outcomes as found in randomized controlled trials. The strategic use of MTS within a smoking cessation program is discussed.