There can be few people who believe that parental smoking is not harmful to children's health. Maternal smoking in pregnancy is a cause of poor intrauterine growth and the exposure of children to environmental tobacco smoke increases their risk of otitis media and respiratory symptoms.  Data from the US Third National Health and Nutrition Examination Survey (NHANES III) of 1988–94 (David M Mannino and colleagues. Archives of Pediatrics and Adolescent Medicine2001;155:36–41) have been used to compare non-smoking 4–16 year old children in successive tertiles for serum cotinine concentration. Children in the top tertile, compared with those in the bottom tertile, had significantly more wheezing, school absence, and impairment of lung function. In children aged 4–6 years high cotinine was associated with a greater likelihood of a diagnosis of asthma.  So what are we going to do about it? In California (Eliseo J Pérez-Stable and colleagues. Ibid: 25–31; see also editorial, Ibid:15–16) family physicians were more likely than paediatricians to become involved in helping parents to stop smoking by giving the appropriate pamphlets, suggesting that they name a “quit date”, arranging to see them again to discuss stopping smoking, referring them to a smoking cessation programme, or recommending nicotine replacement treatment. Paediatricians had less faith in parents' wish to stop smoking and their own ability to provide antismoking advice. In the editorial a strong case is made for paediatricians getting involved.  The organisation of clinical practice in Britain is different and many or most paediatricians here would probably look upon the nitty-gritty of smoking cessation as the general practitioner's province. Nevertheless, a paediatric consultation is, at least, an opportunity to broach the subject.