First paragraph: Maternal smoking during pregnancy carries significant risks to mother infant and child. Smoking during pregnancy is associated with an increased risk of ectopic pregnancy, placental previa and abruption, preterm premature rupture of membranes, fetal growth restriction, preterm delivery, oral facial clefts, and sudden infant death syndrome. One of the most measurable effects of smoking is approximately doubling the risk of delivering a low birth weight infant. This special issue of the journal highlights the continued risks of smoking in pregnancy and the importance of policies and interventions to address this issue, despite the progress that has been made in reducing smoking in pregnancy in some countries. New data on risks, incidence, interventions and women’s own perspectives are highlighted. Together the included papers provide new data examining key issues in the field, from a wide range of countries.