We encountered a case of intraabdominal hemorrhage caused by celiac artery dissection in a 74-year-old man. Angiography revealed the characteristic string-of-beads sign, irregular alternating arterial dilatations and stenoses giving a rosary-like appearance, which we suspected was caused by segmental arterial mediolysis （SAM） in the branches of the superior mesenteric artery （SMA）; these findings were observed in two locations along the pancreaticoduodenal artery and at one point along the small gastric branch. The patient was managed conservatively and the splanchnic arterial aneurysm believed to be the origin of the hemorrhage, as well as the aneurysm along the small gastric branch, resolved. There are no established criteria for invasive treatment of splanchnic artery aneurysms but this case suggests that thorough follow-up is necessary in cases of SAM.