A case of an aneurysm of the left sinus of Valsalva ruptured in the right atrium is reported. This anomaly was diagnosed in a 30 year old woman who had a continuous systo-diastolic murmur and no signs of cardiac failure. The diagnosis of aneurysm of the left sinus of Valsalva was been determined using 2-D echocardiography, Cardioangiography, in addition, enabled us to recognize the fistula which connected the left sinus of Valsalva with the right atrium. The rarity of this case is supported by two pieces of data: A) aneurysms of the left sinus of Valsalva are the rarest of the sinus of Valsalva aneurysms; B) generally the sinus of Valsalva aneurysms rupture into the adjacent cardiac cavities, while the anomalous fistolous conduits are quite uncommon. The case reported confirms that from an aneurysm of the sinus of Valsalva an atypical fistolous conduit may arise. This could be detected by cardioangiography. In addition echocardiography, is very important, at least as a preliminary examination, for the diagnosis of the sinus of Valsalva aneurysms.