Much knowledge of coronary artery disease and much of the progress in surgical treatment of coronary artery disease has been directly dependent upon the safety with which coronary arteriography has been performed. This safety depends upon the ease of placing the contrast media in the arteries and on the toxicity of the contrast medium itself. This review deals with contrast media toxicity in coronary arteriography, as distinct from toxicity in angiocardiography and other angiography.24