The aim of this study was to compare the mortality associated to primary angioplasty and thrombolysis in patients managed for an elevated ST-segment acute coronary syndrome in less than or more than 3 hours after the onset of symptoms. We analyzed the in-hospital mortality of 846 patients (including 276 [33%] treated by primary angioplasty, 511 [60%] by thrombolysis, and 59 [7%] without revascularisation) included from October 2002 to December 2003 in a registry of patients with an elevated ST-segment acute coronary syndrome managed in less than 12 hours in Northern Alps districts. The overall in-hospital mortality was at 6.0% (51/846). For the 631 managed in <3 hours, the mortality rates were respectively at 5.0%, 4.6% and 11.1% respectively in case of primary angioplasty, thrombolysis and without revascularisation (p=0.21). For the 215 patients with pain lasting more than 3 hours, the mortality rates were at 2.7%, 10.3% and 21.7% in case of primary angioplasty, thrombolysis and no revascularisation, respectively (p=0.01). In the multivariable analysis, the OR of death in case of thrombolysis compared to primary angioplasty was at 1.65 (95% IC: 0.73 - 3.75) for patients with pain " 3 hours, and 4.98 (95% IC: 1.32-18.37) for those with pain > 3 hours. These results are in line with randomized trials conclusions and confirm the international guidelines suggesting primary angioplasty for patients with a chest pain >3 hours and either angioplasty or thrombolysis in case of chest pain < 3 hours.