Purpose: To clarify the positional relationships of abdominal aorta (Ao) landmarks by way of observations from the intravascular space to facilitate angiography. Methods: A total of 95 donated Japanese cadavers were observed. We excluded 32 cadavers with anatomical variation at the celiac trunk (CT) or superior mesenteric artery (SMA), with flexure exceeding 5° in the aorta located cranially to the renal artery (RA), and with flexure exceeding 60° in the aorta located caudal to the RA. The maximum longitudinal diameter of the left (Lt.) RA was measured and the Ao was incised by frontal section to acquire photographs of the intravascular space. The inner diameter of the Ao at the Lt. RA level was investigated. The distances between the inferior borders of the CT, SMA, and Lt. RA were also used as the hypotenuse of a right-angled triangle. Lines parallel to the longitudinal diameter of the Ao and those parallel to the transverse diameter of the right-angled triangle were measured by a computer, and expressed as relative distance indexes using the transverse diameter of the aorta at the Lt. RA level as a reference point. The angle between the transverse axis of the Ao and the line connecting the CT to the SMA was also investigated. Results: The mean diameter of the aorta was 20.6 ± 2.0 mm. The indexes between each blood vessel (longitudinal/transverse) were as follows: Lt. RA to CT 1.69/0.41, Lt. RA to SMA 0.86/0.51, and CT to SMA 0.82/0.13. The mean angle between the transverse axis of the Ao and CT to SMA was 81.9° ± 9.5°. Conclusion: These indexes should contribute to improving skills for workers new to angiography, and may reduce patient risk. [ABSTRACT FROM AUTHOR]