AbstractAnatomic variations are often responsible for a variety of clinical conditions. In this review we investigate compression of the celiac artery and the superior mesenteric artery by the median arcuate ligament (MAL), diaphragmatic crura, or the celiac nerve plexus. This clinical condition known as celiac artery compression syndrome (CACS) has proven controversial in definition and relevance. This condition was first described as chronic abdominal pain because of the mesenteric ischemia caused by extrinsic compression of the celiac artery. Dunbar and others presented surgical approaches to decompress the celiac artery by releasing the MAL. Definitive answers have been sought to classify and relieve the clinical symptoms patients experience postprandially. Persistent symptoms following surgical treatment for CACS have led investigators to question the existence of this disease. Advances in technology such as angiographic MRI and color duplex ultrasonography have refreshed the importance of considering compression of the celiac artery during differential diagnoses. Because of the varying anatomic etiologies of disease, it is not possible to pinpoint a single cause for CACS. Potential etiologies for compression of the celiac artery include a “high take off” origin of the celiac artery compressed by normal diaphragmatic crura and MAL, a normal origin of the celiac artery with long diaphragmatic crura and MAL, large bilaterally fused celiac ganglia (with or without the involvement of the superior mesenteric ganglia) compressing the celiac trunk, celiacomesenteric trunk compression by diaphragmatic crura and MAL, or combinations of the above mentioned entities. In this review we describe potential sources of compression of the celiac artery by regional structures and treatments of CACS in an effort to justify the relevance of CACS in modern medicine. Clin. Anat. 20:612–617, 2007. © 2007 Wiley‐Liss, Inc.