A 39-year-old hypertensive man with severe aortic stenosis underwent aortic valve replacement monitored by intraoperative transesophageal echocardiography. Upon weaning the patient off extracorporeal circulation, hemodynamics became severely compromised, with hypotension, tachycardia, and elevated precordial electrocardiographic tracings. The echocardiographic images were instrumental during the episode to demonstrate that the anterior wall presented hypokinesis consistent with ischemia in the region but that there were also images of hyperrefringence highly suggestive of intracoronary air embolism. Intraoperative transesophageal echocardiography allowed us to diagnose the real cause of the ischemic event and rule out an atheromatous plaque as the source. Perfusion pressure was increased to treat the air embolism. The echocardiographic image demonstrated success, specifically restoration of left ventricular regional contractility. This experience revealed the usefulness of transesophageal echocardiography in intraoperative monitoring to diagnose ischemia, assess the cause, and guide treatment.