1. The presence of left main coronary artery disease (LMCAD) increases both the risk and the importance of coronary arteriography, an essential in the selection of patients for aortocoronary bypass surgery. 2. Our experience in the performance of 67 coronary arteriographies in 51 patients with significant LMCAD contradicts published views and shows that the Judkins method can be used with safety in the presence of LMCAD. 3. Clinical judgment and technical competence are of particular importance when coronary arteriography is done in the presence of LMCAD. 4. Careful patient evaluation with precautionary measures—skilled, meticulous catheterization technique, vigilant catheter tip pressure monitoring, a logical progressive plan of examination and adequate postangiographic care—help to minimize complications in examination of patients with LMCAD.