The visualization by contrast media of the abdominal aorta and its branches is generally recognized as an important, and often indispensable, aid in the surgical management of occlusive and aneurysmal arterial diseases. The fear of serious and even fatal complications that have been observed, however, has raised doubt in the minds of many about the extent to which the clinical application of abdominal aortography is justified. In order to obtain a more precise idea than hitherto available of the magnitude of this risk, we surveyed in detail the clinical histories of 1,502 cases in which 2,399 abdominal aortograms and 910 femoral arteriograms were made in the Henry Ford Hospital. This report is a compilation of our observations and conclusions. Clinical Material Indications for Angiography. —The clinical material under study is summarized in Table 1. In clarification of the scope and type of this clinical experience, it should be noted that