Smoking during pregnancy is harmful to both the foetus and the woman herself. However, in spite of educational efforts, a substantial proportion of pregnant women continue to smoke and many women who do stop smoking during pregnancy resume smoking following childbirth. To foster successful maternal smoking cessation, public health professionals need to focus on the major determinants of smoking and cessation during and after pregnancy, and then to address these with their intervention efforts. It is important to review contemporary epidemiological evidence on this significant public health issue. We have identified nine cohort studies, published in international peer-reviewed journals, that have examined determinants of smoking and cessation in pregnant women. The results indicate that the determinants of pregnant smoking and cessation include maternal age, dose and duration of smoking, partner's smoking habit, socioeconomic status, level of education, age to start smoking, level of addiction, parity and passive smoking. However, many other psychosocial factors, which may affect smoking status among pregnant women, remain to be identified. Evidence reviewed here suggests that a more focused, integrated approach and a more comprehensive assessment of major determinants of smoking and cessation during pregnancy will be required as part of any future intervention effort.