In this case report, a young woman with gallbladder sludge and acute pancreatitis due to acute hepatitis A (HAV) is presented. She was admitted to our hospital with abnormal hepatic enzymes. Five days prior to her admission, an initial abdominal ultrasound was performed at another hospital and revealed no abnormality, while her serum aspartate aminotransferase (AST) level was at the upper limit of normal (ULN) x 8. A second ultrasound was performed at our hospital and revealed a gallbladder wall thickness (9.3 mm), gallbladder sludge in the gallbladder lumen, pancreatic edema, ascites, and hepatomegaly while AST was at the ULN x 50. Magnetic resonance imaging and magnetic resonance cholangiopancreatography revealed imaging features of an acute stage of pancreatitis and gallbladder wall thickness with coexisting sludge in the gallbladder lumen. HAV infection was diagnosed by the detection of immunoglobulin M against HAV in the serum. The patient underwent two repeated abdominal ultrasound examinations on the 5th ( AST was at the ULN x 3) and the 20th days ( AST was at the normal) after her discharge, and both revealed normal findings. In our case, we observed reversible changes in the hepatobiliary and pancreatic system which was related to the severity of hepatic necroinflammation. HAV-associated pancreatitis may be due to the formation of biliary sludge during the acute phase of the viral illness, but this association needs further investigation. Copyright (C) 2006 S. Karger AG, Basel and IAP.