Nonocclusive mesenteric ischemia (NOMI) is a rare complication that occurs in about 0.05% of patients after openheart surgery, and NOMI refers to the mesenteric ischemia that’s caused by splanchnic vasospasm without occlusion of the great intestinal vessels. In the presently reported case, NOMI developed to maintain the blood flow to the heart and brain after several minutes of a hypotensive status and the latter was caused by acute aortic dissection that complicated an aortic cannulation procedure. Unfortunately, the patient died even though the problems were diagnosed early and proper treatment was administered. Early diagnosis of NOMI by angiography and the selective infusion of vasodilators are thought to be the only way to improve survival for patients with clinically suspected NOMI.