Abstract: In patients with acute myocardial infarction, mechanical revascularization by percutaneous coronary intervention can effectively reduce mortality. However, a substantial proportion of patients with acute myocardial infarction develop chronic cardiac failure, despite restoration of epicardial vessel patency. It is found that the phenomenon of "no-reflow" caused by coronary microvascular obstruction and the subsequent myocardial hemorrhage are the important factors involved in this process. Understanding of the role of intramyocardial haemorrhage in the no-reflow phenomenon and myocardial injury is crucial to the development of new therapeutic strategies to treat acute myocardial infarction. In this article, we reviewed the latest development in pathophysiology, imaging, clinical significance, and therapeutic strategies of intramyocardial hemorrhage.