This study evaluated the efficacy of a 6-week forced ban on smoking and brief behavioral counseling on long-term smoking rates. Participants were active-duty enrollees in U.S, Air Force basic military training over a 1-year period (N = 25,996). All participants were under a 6-week ban from tobacco products, and 75% were randomized to a brief smoking cessation intervention, with the other 25% randomized to a control condition. At 1-year follow-up, 18% of smokers were abstinent; women, ethnic minorities, and those intending to stay quit at baseline were more likely to be abstinent. Among smokers not planning to remain abstinent at baseline, those receiving the intervention were 1.73 times more likely to be abstinent. Over time, substantial smoking initiation occurred among nonsmokers (8% of never smokers, 26% of experimental smokers, and 43% of ex-smokers). Forced cessation is associated with good levels of long-term cessation, and brief behavioral interventions enhance cessation in certain subgroups.