Results are described on the effect of limitation of the infarction zone on the course of IHD during the first year of observation in 320 patients with a history of myocardial infarction (MI). The clinical course of the disease and changes of tolerance of physical load were studied in two groups of patients. In one of the groups limitation of the infarction zone was realized during the first ten days. It was found that limitation of the infarction zone is of importance only in the acute period of MI reducing the frequency of fibrillations and lethal outcomes. Limitation of the infarction zone did not effect the course of IHD during the first postinfarction period. Infarction in the involved zone showed no increases in frequency.