Sixteen hospitals in Sweden, including those in urban and more sparsely populated areas, and the associated ambulance organizations were enrolled in a prospective evaluation of the feasibility of treating patients with a ST-elevation infarction with a thrombolytic agent (reteplase) before hospital admission. A physician staffed the ambulances in 1% of cases, a nurse in 67%, and a staff nurse in 32% of cases. In all, 64 patients in urban areas and 90 patients in rural areas were included. The occurrence of complications before hospital admission was low and similar in the 2 groups. The median interval between the onset of symptoms and the start of thrombolysis was 1 hour 44 minutes in urban areas versus 2 hours 14 minutes in rural areas (P = 0.03). The median arrival time (interval between onset of symptoms and arrival of the ambulance) tended to be shorter in urban areas (1 hr 10 min vs 1 hr 33 min; not significant) and the median interval between the arrival of the ambulance and the start of thrombolysis was shorter in urban areas (27 min vs 36 min; P < 0.0001). When comparing urban areas with the least-populated rural areas, differences in various delay times became even more marked. Patients in urban areas had a higher ejection fraction and fewer symptoms of heart failure after 30 days and a lower 1-year mortality.