The aim of this work was to study the prevalence of smoking in an urba
n population from cities with low environmental pollution. From a samp
ling of basic and high school children, 1959 subjects coming from 406
homes were selected for the study and answered a questionaire about sm
oking. The adjusted prevalence of smoking among subjects older than 10
years old was 36,5% and 40,8% in subjects older than 15 years old. Pr
evalence in males was 49,4% and 35% in female. However among subjects
between 10 and 15 years old, females had a higher prevalence of smokin
g. Most subjects smoked 1 to 9 cigarettes/day, always aspirated smoke
and consumed all the cigarette. The prevalence of passive smokers was
65,5%. It is concluded that the prevalence of smoking is high, that wo
men are starting to smoke earlier than men and that no effort is being
made to stop this habit.