Echocardiography plays an important role in the diagnosis and triage of patients with AMI. It is a most useful bedside tool to help in the diagnosis, monitoring and guiding subsequent management of the critically ill patients who develop complications of MI. in this chapter various post-MI complications are discussed cardiac rupture, Dressler’s syndrome, ventricular free-wall rupture, intramyocardial dissecting hematoma, ventricular septal rupture, mitral regurgitation, and so on, along with their detection with echocardiography. With early reperfusion and closed monitoring the overall mortality with AMI has markedly reduced not only in uncomplicated cases but also in patients with dreadful complications. The diagnosis of infarct expansion, reinfarction, or post infarction ischemia can be made with echocardiography or nuclear imaging. Echo in the unstable patient with AMI is a highly demanding procedure to be performed by experienced professionals.