AIMS: Stent thrombosis is a serious complication of percutaneous coronary intervention (PCI). We examined the incidence of stent thrombosis and other outcomes in patients treated with PCI and paclitaxeleluting stents (PES), sirolimus-eluting stents (SES) or bare-metal stents (BMS). METHODS AND RESULTS: All patients who underwent PES, SES or BMS implantation from January 2002 to June 2005 were identified in the population-based Western Denmark Heart Registry. All were followed for 36 months. Cox regression analysis was used to estimate relative risk (RR), controlling for covariates. A total of 12,374 patients were treated with stents: 1,298 with PES, 2,202 with SES and 8,847 with BMS. The three-year incidence of definite stent thrombosis was similar in the DES group (1.1%) and in the BMS group (0.7%) (adjusted relative risk [RR]: 1.24; 95% confidence interval [CI]: 0.85-1.81). Very late definite stent thrombosis occurred more frequently in DES-treated patients (adjusted RR: 2.89, 95% CI: 1.48- 5.65). The three-year mortality rate did not differ significantly between the two groups. Target lesion revascularisation (TLR) was lower in DES-treated patients than in BMS-treated patients (adjusted RR: 0.71, 95% CI: 0.63-0.81). CONCLUSIONS: An increased risk of very late definite stent thrombosis was observed in DES-treated patients compared with BMS-treated patients, but a similar mortality was detected. TLR continued to be lower among patients receiving DES.