Nicotine replacement therapies (NRT) are an effective treatment for tobacco dependence, yet most smokers do not quit or remain abstinent. We investigated whether Swedish snus (snuff) use was associated with smoking cessation among males participating in a large population based twin study in Sweden. Snus use was associated with smoking cessation but not initiation. Given that snus delivers comparable nicotine concentrations but carries lesser cancer risk than cigarettes, snus may be a widely used, non-medical form of NRT. Evaluation of the efficacy of snus for smoking cessation should be evaluated in randomised clinical trials.