Tobacco Smoke (TS) exposure is an important cause of pediatric morbidity and mortality worldwide. Estimates suggest that over 50% of US children are exposed to tobacco smoke, and 40% of children internationally. TS exposure has been linked with many specific diseases and social conditions. It is especially prevalent amongst children who live in poverty, and is associated with increased rates of food insecurity. Children who are exposed miss more school, and thus may miss important educational opportunities. Compounding this, exposed children show deficits in cognitive abilities, and increased behavioral problems. TS causes oxidative stress and changes in the immune system, which may result in lower antioxidant levels, and increased rates of asthma and other atopic diseases. In addition to asthma, TS exposure increases the risk and severity of respiratory diseases, including bronchiolitis and tuberculosis. TS exposure in children has been associated with diseases of other systems as well, including inflammatory bowel disease, leukemia, dental caries, and sudden infant death syndrome. Finally, we are starting to understand that the link between TS exposure and cardiovascular disease may begin in childhood, with exposed children having higher rates of metabolic syndrome, and measurable changes in their vascular contractility. Efforts need to continue worldwide to prevent childrens exposure to this toxic and harmful product.