AbstractMyocardial scintigraphy with99mtechnetium‐pyrophosphate was performed in two selected groups of patients, consisting of 20 who had acute myocardial infarction (AMI) clinically and 18 who had no AMI clinically. The purpose was to estimate the value of this method in the detection or disproof of AMI compared with usual procedures (ECG and serum enzyme determination — GO‐transaminase and α1‐fraction of LDH).Each of the 20 patients with clinical AMI had positive scintigrams. There were no false‐negative findings. Out of 18 without AMI, 15 had negative scintigrams; in the other 3, scintigraphic findings were false‐positive.The prevalence of AMI among patients admitted to the cardiological department was 0.39. In this population of patients, the calculated predictive value of a positive scintigram was 0.80, whereas the predictive value of a negative was 1.0. In patients admitted to the coronary care unit, the prevalence of AMI was 0.51; the corresponding predictive values of a positive scintigram was 0.86 and of a negative 1.0.The identity between scintigraphic and electrocardiographic infarct localization was good. Infarct size estimated by scintigraphy was not significantly correlated to the maximum elevation of serum enzyme concentration.In patients suspected of having AMI, it is highly probable that a negative scintigram obtained from day 2 to day 6 after the onset of symptoms will rule out the presence of acute myocardia