Aims: Potential exists for improving the impact of quit-smoking programmes, by recruiting smokers in early motivational stages, by using active recruitment strategies, and by offering professional assistance to quit. Methods: This was a randomized population-based intervention study, in Copenhagen, Denmark. A total of 2,408 daily smokers in all motivational stages were included. All participants completed a questionnaire, and underwent a health examination and a lifestyle consultation. Smokers in the high-intensity intervention were offered assistance to quit smoking in smoking cessation groups. Results: Before the lifestyle consultation only 11% of the smokers stated that they planned to quit within one month. After the lifestyle consultation 27% accepted smoking cessation in groups and an additional 12% planned to quit without assistance. Of the smokers who accepted smoking cessation groups 23% had not been planning to quit before the lifestyle consultation. Being a woman, having high tobacco consumption, having a long smoking history, having tried to quit within the previous year, and having a higher motivation to quit predicted participation in smoking cessation groups. Conclusions: It was possible to recruit a large number of smokers in early motivational stages by using active recruitment strategies and by offering assistance to quit. Lifestyle consultations markedly increased the number of smokers willing to try to quit. Smokers preferred assistance to quit in a smoking cessation group to quitting on their own; therefore, it is important to improve recruitment strategies for smoking cessation programmes.