A 58-year-old Japanese woman came to our institution because of leg edema and abdominal distention. She had developed acute pancreatitis 5 times in the past 3 years. Dilation of the bile duct and main pancreatic duct without obstruction was observed on computed tomography and magnetic resonance cholangiopancreatography. The presence of Strongyloides stercoralis was highly suspected from the biopsy sample from the duodenal papilla. Polymerase chain reaction amplification and sequencing of small subunit rDNA from paraffin-embedded specimens identified the worm as S. stercoralis. All of the symptoms were considered to be associated with S. stercoralis infection. Therefore, the patient was treated with oral administration of ivermectin. Subsequently, symptoms and laboratory data improved. There has been no recurrence of the symptoms to date.