The organ of Zuckerkandl is a chromaffin body derived from neural crest located at the bifurcation of the aorta or at the origin of the inferior mesenteric artery. It can be the source of a paraganglioma.

The term para-aortic body is also sometimes used to describe it, as it usually arises near the abdominal aorta, but this term can be the source of confusion, because the term "corpora paraaortica" is also used to describe the aortic body, which arises near the thoracic aorta. This diffuse group of neuroendocrine sympathetic fibres was first described by Emil Zuckerkandl, a professor of anatomy at the University of Vienna, in 1901.

Some sources equate the "aortic bodies" and "paraaortic bodies", while other sources explicitly distinguish between the two. When a distinction is made, the "aortic bodies" are chemoreceptors which regulate circulation, while the "paraaortic bodies" are the chromaffin cells which manufacture catecholamines.

Organs of Zuckerkandl (O of Z) harbor the potential for deadly paragangliomas. Paragangliomas are one of the surgical causes of hypertension. Major treatises of medicine offer very little information on this topic.