The aim of our study was to better understand processes of ongoing smoking or smoking cessation (quitting) following hospitalisation for myocardial infarction or unstable angina (acute cardiac syndromes). In-depth interviews were used to elicit participants’ stories about ongoing smoking and quitting. In total, 18 interviews with smokers and 14 interviews with ex-smokers were analysed. Our findings illustrate the complex social nature of smoking practices including cessation. We found that smoking cessation following hospitalisation for acute cardiac syndromes is to some extent a performative act linked to ‘doing health’ and claiming a new identity, that of a virtuous ex-smoker in the hope that this will prevent further illness. For some ex-smokers hospitalisation had facilitated this shift, acting as a rite of passage and disrupting un-contemplated habits. Those participants who continued to smoke had often considered quitting or had even stopped smoking for a short period of time after hospitalisation; however, they did not undergo the identity shift described by ex-smokers and smoking remained firmly entrenched in their sense of self and the pattern of their daily lives. The ongoing smokers described feeling ashamed and stigmatised because of their smoking and felt that quitting was impossible for them. Our study provides an entry point into the smokers’ world at a time when their smoking has become problematised and highly visible due to their illness and when smoking cessation or continuance carries much higher stakes and more immediate consequences than might ordinarily be the case.