Pancreatic disease is the most frequent cause of isolated splenic vein thrombosis. Splenic vein thrombosis causes a localized form of portal hypertension known as sinistral or left-sided portal hypertension. Splenic vein thrombosis may be complicated by the formation of gastric varices, with the potential of massive upper gastrointestinal bleeding. Whereas splenectomy is considered to be the treatment of choice for symptomatic splenic vein thrombosis, the role of splenectomy in the patient with asymptomatic splenic vein thrombosis remains controversial. We report a rare case of acute pancreatitis complicated by isolated asymptomatic splenic vein thrombosis. Recognition of this disease entity is important because the risk of secondary variceal bleeding, while uncommon, can be life-threatening.