BACKGROUND: Thrombolytic treatment substantially reduces mortality and morbidity in acute myocardial infarction. This survival benefit rapidly declines when thrombolysis is delayed. In our department this delay has previously been measured to be 40 (10-360) minutes. It is important to reduce this time loss. MATERIAL AND METHODS: From two ambulances, 168 patients ECGs were recorded and transmitted to the coronary care unit (CCU) where they were interpreted by a cardiologist or an internist. Patients with an ECG diagnostic of acute myocardial infarction were taken directly to the CCU by-passing the emergency room. In the CCU the nurses were ready to start thrombolytic treatment once consent was given. RESULTS: All 168 ECGs were of excellent quality. 16 of the ECGs transmitted were diagnostic of an acute myocardial infarction. In 15 patients the diagnosis of acute myocardial infarction could be verified on arrival. These were thrombolized at median 15 (8-32) minutes after their arrival at the hospital entrance. INTERPRETATION: Pre-hospital recording and interpreting of ECGs can markedly reduce the time delay between the arrival at the hospital and the starting of thrombolysis in patients with ECGs diagnostic of acute myocardial infarction.