A variation in liver vascularization was discovered in a 50-year-old man. A single common hepatic artery was found to be responsible for vascularization of the entire liver. This artery was unusual in that it formed the first branch of the superior mesenteric artery, crossing the portal trunk shortly after its origin, and passed in front of the portal vein to reach the hilum of the liver, where it divided into a right and a left branch. This artery was a true common hepatic artery because a gastroduodenal artery emerged from it 2 cm after its origin. A common hepatic artery originating from the mesenteric artery and passing in front of the portal vein has never been described before. The patient had a second anatomical variation: the left gastric artery and the splenic artery arose directly from the aorta, without celiac trunk separation. This observation confirms the importance of carrying out a precise vascular assessment before all types of hepatic or pancreatic surgery, to identify possible variations in the number or trajectory of hepatic arteries.