A safe technique for selective coronary arteriography is described which allows demonstration of the coronary arterial tree by standard biplane angiography and percutaneous cathe-terization of the femoral artery. This is accomplished with special catheters which do not dislodge from the coronary arteries when successfully introduced, do not significantly decrease coronary flow and can, therefore, remain in place for a longer period of time. Demonstration of small coronary arteries is feasible and definite identification of the various coronary branches is possible with one single injection. Maximal vascular detail superior to cineangiography can be obtained. Results, technique, complications, and the atrial circulation and its role in collateral flow are discussed. Demonstration of the anatomy is followed by assessment of tissue flow by xenon flow measurement.