Tobacco use is an alarming public health problem worldwide and causes significant morbidity and mortality. Globally, 22% of the world’s population over 15 years are smokers. Smoking affects both male and female fertility in their reproductive age. Smoking during pregnancy is one of the single most important avoidable cause of adverse pregnancy outcomes. This work provides an overview of the determinants of smoking and smoking cessation during pregnancy and postpartum, based on the levels of the socio-ecological model. A qualitative study explored knowledge, beliefs and practice among midwives and gynaecologists concerning smoking cessation among pregnant women. The second study tested the factorial structure, validity and reliability of the Dutch version of the Modified Reasons for Smoking Scale in a sample of smoking pregnant women. The third study obtained insight into the associations between smoking patterns and depressive feelings during pregnancy and postpartum, taking into account several sociodemographic characteristics. The final study analysed the association between smoking cessation beliefs and smoking status, and between smoking cessations beliefs and intention to quit smoking, using the Theory of Planned Behaviour in pregnant smokers and ex-smokers. After presenting and discussing the results, recommendations and directions for further research are formulated, based on the socio-ecological model.