In the Syrian Arab Republic, studies on the effects of environmental tobacco smoke on children are lacking. We conducted a cross-sectional study on the effect of household environmental tobacco smoke on 1859 children under 12 years from both urban and rural areas. Parental and household smoking were associated with respiratory morbidity in the children. Parental smoking was associated with an increased likelihood of having sudden infant death syndrome in the family and was also associated with the presence of other smokers within households, which adds to children's exposure. To our knowledge this is the first study in the Syrian Arab Republic to report a clear association between environmental tobacco smoke and childhood respiratory morbidity.