Selective coronary artery visualization was performed in the CCU by means of a movable fluoroscopy device in 96 patients with suspected myocardial infarction within 6 hours after onset of symptoms. Intracoronary streptokinase (SK) was administered in a total dosage of 200 000 to 400 000 U within 30-60 min to 69 patients with complete (N = 57) or subtotal obstruction (N = 12) of the infarct-related vessel. Recanalization was achieved in 39 of the 57 patients (68%) with initially complete occlusion. Three of the 39 successfully treated patients died (7.7%) versus 8 of 33 subjects (24%) with persistent complete obstruction (chi-square 3.21, not significant). Selective cineangiography subsequently performed in 8 patients and postmortem examination of 12 subjects who had died, showed that all haemodynamically significant lesions had been recognized by the examination in the CCU with one exception. It is concluded that intracoronary thrombolysis performed in the CCU, by means of a standard mobile fluoroscopy equipment is effective, safe, inexpensive and may be started virtually without delay after admission.