BACKGROUND: Pre-hospital thrombolysis is a relatively new treatment modality in Norway. The present study is a county-based evaluation of the first phase of this procedure after its introduction in 2002. MATERIALS AND METHODS: This is a retrospective cohort study of all patients who, over a nine-month period, had a pre-hospital ECG taken by paramedics and transmitted to the county's two coronary care units. The medical records of all patients who received pre-hospital thrombolysis were analysed and compared with those who received in-hospital thrombolysis over the same period. MATERIAL AND METHODS: A pre-hospital ECG was successfully taken and transmitted in 840 patients. Pre-hospital thrombolytic therapy was given to 45 (5.4%) patients, of whom 38 (84%) developed ST-elevation myocardial infarction (STEMI). Over the same period, 32 patients received in-hospital thrombolysis, of whom 28 (87%) developed STEMI. Among the 738 hospitalised patients who did not receive pre-hospital thrombolytic therapy, 218 (28%) had a diagnosis of acute coronary syndrome, 258 (35%) had established coronary heart disease but no evidence of coronary ischaemia, while 262 (36%) had no evidence of coronary heart disease at all. Median call-to-thrombolysis time was 42 minutes (range 21-75). INTERPRETATION: The findings indicate good paramedical pre-hospital routines with short call-to-thrombolysis-time, but the routines for pre-hospital ECG and thrombolytic therapy need reassessment.