A previously healthy, 31-year-old man was evaluated in the emergency department after being violently assaulted. A harsh, continuous murmur was noted on physical examination. Transthoracic and transesophageal echocardiograms were interpreted as showing a ruptured sinus of Valsalva aneurysm with a shunt into the right atrium and a tricuspid valve vegetation. The patient was treated with antibiotics for presumed endocarditis. Subsequent echocardiographic and surgical evaluation showed no evidence of past or present endocarditis. Rather, the sinus of Valsalva aneurysm and rupture gave the appearance of a valvular mass. This report shows some of the potential pitfalls in the delineation of abnormalities related to sinus of Valsalva aneurysms and rupture.