We report herein the case of a 56-year-old man found to have an isolated dissecting aneurysm of the superior mesenteric artery (SMA) after he presented with a 3-day history of postprandial epigastralgia of sudden onset. An echogram showed marked dilatation of the SMA and a high level of peripheral echoes in a linear fashion within its lumen. A thin-section contrast enhanced computed tomography revealed a thin flap, separating two distinct well-enhanced lumina. Angiography confirmed the presence of a localized dissecting aneurysm of the SMA. The patient was treated conservatively and has since been followed up as an outpatient. Following the presentation of this case, the problems regarding the diagnosis and management of this rare disease are discussed based on a review of the literature.