In 1989, a postal survey was undertaken to investigate the smoking prevalence and attitudes of Gwynedd Health Authority employees towards the Authority's non-smoking policy, passive smoking and other related issues. The results show a smoking prevalence rate of 22% for those participating in the survey, with over half of all smokers expressing a wish to stop. Although the rate was similar for males and females, it was marginally higher amongst nursing staff and young employees. Smoking prevalence was highest among the ancillary staff, and lowest among the medical and dental professions. Most employees were in broad agreement with the Authority's non-smoking policy, and a majority thought it about right or favoured extending it. Most non-smokers and ex-smokers believed passive smoking to be a health hazard, with an increased number rating it anti-social. Attitudes towards these issues were similar for males and females, with marked differences between the groups employed in different areas of the service. Younger employees were more aware of the dangers of passive smoking, but less sympathetic towards the policy than the older ones. The findings of this study highlight the differences between smokers and non-smokers on all smoking issues. The implications for health education and the Authority's non-smoking policies are discussed.