The rare case of a coronary fistula from the left anterior descending branch to the left ventricle is presented. The 38 year old woman was admitted with homonymous quadrantanopsia and hyperacusis. An abnormal Ecg and a systolic and diastolic murmur of unknown origin were discovered. Cardiac catheterization yielded normal findings. Coronary angiography demonstrated an aneurysma of the dilated left anterior descending coronary artery with a fistulous communication into the left ventricle. This congenital left to left shunt produced a typical mid-diastolic murmur clearly separated from the systolic murmur.