We describe two cases of left atrial myxoma, demonstrating an unusual tumor vascularity as revealed by coronary angiograms. Both cases had suffered typical episodes of transient ischemic attack (TIA). Coronary angiography revealed tumor blood supply from coronary arteries in both cases, and also a leakage of contrast medium from the surface of the tumor blood vessels to the left atrium in one case. In the medical literature available in English reviewed so far, no report of such a leakage has been reported. Selective coronary arteriography can be a useful diagnostic method of delineating left atrial myxoma and its blood supply.