A 49-year-old man complained of sudden upper abdominal pain but was not given a definitive diagnosis. The day after he was discharged, he noticed left chest pain. An in-depth electrocardiogram indicated acute myocardial infarction, and emergent coronary angiography revealed 99% stenosis of his left coronary artery. An intravascular ultrasound revealed spontaneous coronary artery dissection (SCAD), and the lesion was successfully stented. In an atherosclerosis screening, superior mesenteric artery dissection (SMAD) was confirmed, after which the lesion was successfully stented. This case suggests that SCAD and SMAD might have similar pathological backgrounds.