Transesophageal echocardiography was performed to evaluate the exact cause of severe mitral regurgitation in a 64-year-old man presented with hypotension and dyspnea after acute inferior wall myocardial infarction. In mid-esophageal two- and four-chamber view, the ruptured stump of papillary muscle could not be visualized. However, in transgastric two-chamber view, we could clearly visualize the ruptured head of the posteromedial papillary muscle as a separated mass attached by chorda tendinae, as well as the freely mobile stump of the ruptured papillary muscle within the left ventricle. So, the comprehensive transesophageal echocardiography, including transgastric imaging, is always indicated in patients with severe mitral regurgitation after acute myocardial infarction.