The purpose of this study was to explain smoking habits amongst middle-aged men in Finland by describing their experiences of smoking and their attitudes towards smoking. As a pilot survey for a major health campaign targeted at 40-year-old men, the data for this study were collected using two questionnaires in connection with voluntary medical examinations. The first questionnaire was based on Prochaska's theory of stages of change in health behaviour. The second instrument was an attitude scale developed specifically for this study on the basis of Green and Kreuter's theory of factors influencing health behaviour. According to the results 31% of males aged 40 were regular smokers. Men with a lower level of education and out of work smoked more often than others. Non-smokers reported a better self-perceived health than smokers. Smoking cessation is a process in which men gradually proceed from one step to the next. In this study 12% of the men were in the contemplation stage and 11% in the preparation stage. One-quarter of the men had recently given up the habit and were in the action stage, while 2% had quit smoking over 6 months ago and were in the maintenance stage. One-quarter of the men regarded smoking as an integral part of their way of life and felt that public opinion towards smoking is hostile.