We describe a case of a 49-year-old man who presented with an uncomplicted aortic root aneurysm, aortic insufficiency, and ST-elevation myocardial infarction (STEMI) without obstructive coronary artery disease on angiography. The computed tomo- graphy angiogram (CTA) of the thorax, performed without cardiac gating, was misinterpreted as normal. In retrospect, an overlooked extravasation of contrast material lateral to the aortic root was detected on non-gating magnetic resonance angiography (MRA). Exploration of the aortic root revealed an unsuspected horizontal intimal tear of the left sinus of Valsalva with limited extramural hematoma. The presence of an otherwise silent intimal tear on preoperative imaging studies makes the overall management more problematic. For example, initiating early broad empirical anticoagulants or fibrinolytics therapy to treat the accompanied myocardial infarction may extend the tear into a full life-threatening aortic dissection, tamponade or rupture. We highlight many of the difficulties associated with the diagnosis and treatment of limited sinus tear when aortic root aneurysm is presenting with cryptogenic STEMI. Accurate morphologic characterization of intimal tear would be best defined with either an electrocardiogram-gating CTA or MRA imagings. These non-invasive tests are needed to make appropriate management decisions. Depending on other pathologic components of aortic root, cusps and the commissural geometry, sinus tear is a critical component for the overall treatment plan and it shifts the surgical intervenetion from valve-sparing operation, commissural resuspension and leaflet repair to composite aortic root replacement (modified version of the Bentall procedure).