Acute pancreatitis is a complication of mumps which mainly affects children who then usually acquire permanent immunity. We present the case of a woman with acute pancreatitis caused by mumps re-infection in adulthood. A 34-year-old woman developed mild acute pancreatitis caused by re-infection with mumps, as confirmed serologically by enzyme-linked immunosorbent assays mumps-specific IgM and IgG. Acute pancreatitis was indicated by the elevation of amylase and other pancreatic enzymes such as lipase and elastase-1 as well as by swelling of the pancreatic head visualized by abdominal computed tomography. The abdominal symptoms were resolved soon after the administration of a pancreatic enzyme inhibitor. As the swelling of the right and left parotids decreased, serum amylase levels also gradually normalized. We believe that this is the first reported case of acute pancreatitis caused by mumps re-infection in an adult. Such re-infection should be considered a possible though rare cause of acute pancreatitis in adulthood.