The protective effect of marriage on smoking has been extensively established in the literature. However, less is known about the dynamics of how smoking behaviour is connected to various marital life course events, and whether there are any gender discrepancies in this respect. In this article the connection between the marital life course and smoking is analysed from a stress-related perspective controlling for other socio-economic characteristics. We use information on 81,000 individuals from the Swedish longitudinal micro-level ULF (Survey of Living Conditions) database 1980-2000, which is randomly drawn from the sample population of all Swedes aged 16-84. Logistic regressions on current smoking status and changes in smoking behaviour of participants in the panel part of the data are estimated. The marital life course is strongly linked to smoking behaviour with being or getting married indicating low smoking risks and marital disruption indicating high risks. The divorced smoke to a higher extent than the widowed and there are signs that getting divorced implies higher risks than becoming widowed, both of taking up/relapsing and, for women, not being able to quit. Further, the results indicate that the connection between smoking cessation and living with a partner is stronger for men, whereas women are more affected by the propensity to start smoking after marital disruption. The protective effect of being married on smoking decreases with the age difference between spouses in households where the wife is older than the husband. Taken together, the results yield a rather complex pattern of smoking behaviour over the marital life course. Further, perceived financial stress is strongly connected to smoking and not being able to quit. Controlling for this effect still leaves a socio-economic status gradient in smoking.