Pancreatic pseudocyst rupture into the portal vein is a very rare complication and only three reported cases were confirmed using MRI. We report the case of a 50-year-old man with fistula formation between the pseudocyst and the portal vein, confirmed noninvasively by MRI. T2-weighted MR images and magnetic resonance cholangiopancreatography showed fluid signal intensity within the portal, superior mesenteric, and splenic veins, and a direct communication between the pseudocyst and the portal vein.