The first Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto (GISSI) study showed striking evidence of the effectiveness and safety of intravenous thrombolytic treatment in acute myocardial infarction (MI). Since publication in The Lancet, the original report has become a reference work for every paper which deals with thrombolysis. In addition to GISSI's scientific value, these studies applied formal research to routine clinical practice outside of referral centers. Nearly all Italian CCUs took part in the GISSI projects, so that the results provide a profile of the patient who seeks care for acute MI in Italy. This wide data base allowed GISSI investigators to look into some relevant clinical events, eg, primary ventricular fibrillation, stroke, and in-hospital reinfarction. The GISSI-2 trial followed the GISSI-1 philosophy. The package of treatments recommended after extensive discussion with all the investigators (beta-blocker, aspirin, nitrates) was widely adopted. Now, only five years after the start of the GISSI-1, the overall mortality of Italian patients with acute MI has decreased from 13.0 percent to about 9 percent, and the number of patients with acute MI arriving in hospital within 1 h of the onset of symptoms has increased 50 percent. It is the wish of the GISSI investigators that this approach to treating acute MI will be regarded and acknowledged as their major contribution to the problem.