Background: Effective smoking cessation campaigns require as baseline, precise estimations of smoking habits in different populations. Aim: To assess the prevalence of smoking in academic, non-academics workers and student of the University of Concepción. Material and methods: In a random and stratified sample of 272 workers (including academics) and 1146 students, a previously validated, self administered questionnaire about smoking was applied. Daily smoking was defined as smoking seven or more cigarettes per week and occasional smoking as smoking less than seven cigarettes per week. Results: The prevalence of smoking was 23% among academics, 34% among non-academic workers and 44% among students. Nineteen percent of men and 16% of women were occasional smokers; 23% of men and 25% of women were daily smokers. Students started smoking at 15 ± 2 years old and workers did so at 18 ± 3 years old. The grater influence about smoking came from parents. Workers from the administrative services and from the natural sciences faculty had the higher prevalence of the habit. The total annual cost of smoking was $33,000,000 (US$62,000). Conclusions: The prevalence of smoking at the University of Concepción is higher among students than workers. Quitting programs are urgently needed (Rev Méd Chile 2000; 128: 977-84).