Open access. The global epidemic of tobacco use continues to cause a considerable burden of premature death and disease.1 2 Worldwide, over 1 billion people are regular smokers, and the societal costs of smoking have been estimated at over £1 trillion/year.1 3 Tobacco is relevant to child health in various ways. Unborn children may be exposed to tobacco when their mothers smoke, are exposed to secondhand smoke (SHS) or use smokeless tobacco products. Antenatal tobacco smoke exposure can lead to birth defects, preterm birth, intrauterine growth restriction and stillbirth.4–6 After birth, exposure to SHS increases the risks of neonatal and infant death, otitis media with effusion, respiratory tract infections (RTIs), meningococcal disease and asthma attacks.5 6 Furthermore, early-life tobacco smoke exposure increases the likelihood that the child will become a smoker later in life. In this paper, we discuss how tobacco control measures may improve early life health outcomes and highlight key knowledge gaps.