To resolve the question of whether coronary thrombolysis for acute myocardial infarction is more effective in patients with or in those without chronic preinfarction angina, we retrospectively analyzed cineventriculograms in 54 patients with the first anterior Q-wave myocardial infarction during the chronic stage of myocardial infarction. Patients were divided into 2 groups according to the presence (group A, n = 24) or absence (group B, n = 30) of chronic preinfarction angina. In group A, 16 had either intracoronary (n = 6) or intravenous (n = 10) coronary thrombolysis with urokinase within 6 h after the onset of acute myocardial infarction. In group B, 11 had either intracoronary (n = 4) or intravenous (n = 7) coronary thrombolysis within 6 h after the onset of acute myocardial infarction. Global left ventricular ejection fraction and regional wall motion in infarct areas were evaluated quantitatively. In group A, the percentage of systolic segment shortening in infarct areas was 20 ± (SD) 16% in patients with thrombolytic therapy and 17 ± 15 % in those with conventional therapy (p = NS). By contrast, in group B, the regional wall motion in infarct areas was significantly (p < 0.01) better in patients with thrombolytic therapy compared to those with conventional therapy (13 ± 10 vs. 3 ± 8%). Thus, patients without chronic preinfarction angina might benefit from coronary thrombolysis, while in those with preinfarction angina the beneficial effect of thrombolytic therapy may be relatively limited.