BACKGROUND: It is recommended that general practitioners (GPs) offer cessation advice and pharmacological interventions to smokers with acute coronary syndrome (ACS). The study objective was to describe the extent to which this is done, and to describe outcomes by smoking status. DESIGN: Patients aged 30+ hospitalised for troponin-positive ACS from 2002 to 2009, discharged home alive, were identified in the Myocardial Ischaemia National Audit Project registry. Patient data were linked to the General Practice Research Database, Hospital Episode Statistics, and Office of National Statistics mortality data, enabling a unique perspective of longitudinal smoking data. Patients who smoked prior to the hospitalisation had GP interventions and quitting status established in the 3 months following discharge, and were followed up for major clinical outcomes. METHODS: The outcomes evaluated included death, repeat ACS, stroke, heart failure, and major adverse cardiac events (MACE). RESULTS: Of the 4834 patients included, 965 (20%) were smokers at the time of their ACS. After the ACS event, only 225 (24%) received any GP smoking intervention within 3 months, with 82 (9%) receiving advice only, and 143 (15%) receiving a pharmacological intervention. Patients who quit (320; 33%) were at a decreased risk of mortality (relative risk (RR) 0.49; 95% confidence interval (CI) 0.35-0.69) and MACE (RR 0.61; 0.46-0.80) compared with patients who did not. CONCLUSIONS: Whilst a high proportion of patients with ACS are smokers, there is a low level of GP cessation intervention following hospital discharge. This missed opportunity of patient care is important given the decreased risk of mortality and MACE found amongst those who quit.