AIMS: Patients with diabetes mellitus have poorer outcome following acute coronary syndromes and coronary revascularisation. Knowledge of long-term outcome after revascularisation in real-life situations is though limited was analysed. METHODS AND RESULTS: Patients included in the Swedish Coronary Angiography Angioplasty Registry (SCAAR) in 2002-2007 with no previous revascularisation were followed for mortality after a first PCI until the end of 2007 (mean follow-up time 1,059 days). Differences in background and procedural characteristics were adjusted for in a multivariable Cox regression model. Of 57,708 patients, 18.8% had diabetes. Absolute mortality rate after four years follow-up was after STEMI, non-ST-elevation ACS and stable CAD respectively 23.2%, 17.8% and 12.7% for persons with diabetes and 14.4%, 8.4% and 5.7% for persons without diabetes. Adjusted relative risk for long-term mortality after first PCI was higher in patients with diabetes compared with those without; RR (95% CI); 1.66 (1.33-1.72), and after all three different PCI indications; RR (95% CI) for CAD; 2.01 (1.69-2.40), non-ST-elevation ACS 1.73 (1.58-1.90) and STEMI 1.44(1.30-1.59). CONCLUSIONS: Long-term mortality is higher in diabetic patients compared with those without, after a first PCI and this mortality gap increases with follow-up time. Intensive secondary preventive measures are needed to improve this situation.