The aim of this study was to investigate tobacco habits among ice-hockey-playing boys in three clubs in the County of Värmland, Sweden and to analyse whether health information about the harmful effects of tobacco could change the players' tobacco habits. In addition, the issue of whether there is any correlation between knowledge of tobacco and its harmful effects with tobacco habits was studied. Ice-hockey-players from three ice-hockey clubs were represented and one of the clubs acted as a control group. A total of 252 male ice-hockey-players, 12-19 years old participated. A specially designed questionnaire containing 33 questions on background, socioeconomics, behaviour, and knowledge was used. The boys answered the questionnaire on three occasions. The first and second examinations took place on the same occasion with the intervention occurring between the examinations. The third examination was carried out after 3-5 weeks. The study showed that the use of snuff played a more important role among the ice-hockey-players than did smoking and that they had tried using snuff at the age of 12. The baseline investigation showed that there were no significant differences between the clubs in tobacco habits and knowledge of the harmful effects of tobacco. After the health information, the boys' knowledge of tobacco and its harmful effects increased significantly (p<0.001), but regardless, no change in their use of tobacco was found after 3-5 weeks. Knowledge also increased significantly among the boys in the control group (p<0.001), but no change in the use of tobacco was found here either. No significant difference could be demonstrated between the group of boys who used snuff and the non-users with regard to their knowledge of the harmful effects of tobacco.