600 selective coronary angiographies were performed in 559 patients, using Judkins preformed transfemoral catheters. One fatality was deplored (mortality: 0,17 p. 100). 15 cardiac complications were observed 2,5 p. 100), 10 of which were severe but rapidly corrected arrhythmias. Among these 559 patients 495 were clinically cases suffering from probable or certain coronary heart disease. 88 p. 100 of this group were men. Selective coronary angiography revealed stenosis with decrease of at least 50 p. 100 of the lumen in over 80 p. 100 of the cases. The anterior descending was the most frequent site of stenosis. In the majority of cases, and especially in men, two or several vessels were diseased. There is some relationship between the development of collateral circulation and the extension of coronary disease. In one third of the cases, ventricular function, assessed by measurement of the ejection fraction was impaired.