UNLABELLED: Recent studies still show parental smoke as the number one environmental exposure agent causing asthma in pediatric population. OBJECTIVE: The purpose of this study is to determine the knowledge of parents about the adverse effects of passive smoking and the prevalence of passive smoking in children. DESIGN: Cross sectional study, participants were caregivers of students from first to sixth grade (three private and two public schools) who answered a self-administered survey. Data was analyzed using SPSS. RESULTS: Surveys were collected by availability. Total of caregivers was 594, (47% from private and 53% from public school). The total of estimated children in the survey was 1318, and 48.3% in general had recurrent respiratory illness. Among caregivers, 12.1% (72) reported to be smokers. There were 127 participants who revealed at least 1-3 smokers in their home; these smokers are affecting 167 children who are exposed to secondhand smoke. Among smokers, 16.9% smoked inside the house, 15.5% in their cars and 12.3% smoked in the presence of their children. Participants with higher education had a higher average score on knowledge about adverse effects of smoking (p<.001). Over half of the participants (52%) reported seen anti-smoking promotion on T.V. during previous days. Non-smokers revealed they have seen such promotion recently (p=0.00), but 31% of all participants reported not seen any anti-smoking promotion at all. CONCLUSIONS: The prevalence of smokers in our study was 12.1%. We estimated there was more than one smoker in those households where smoking was allowed. There was a higher prevalence of smokers among parents from public schools. There was no significant difference between passive smoker households and non-smoker households for respiratory illness in their children. Pediatricians are giving information to caregivers about active and passive smoking but still, 34% of smokers reported not receiving any information. We need to reinforce the counseling given to caregivers about the adverse effects of smoking has on environmental pollution, and as a cause of other cancers besides lung cancer, recurrent infections and SIDS.