We describe the sonographic diagnosis of Ascaris-induced acute cholecystitis and pancreatitis in a 2-year-old girl. Abdominal sonography revealed a grossly distended gallbladder with a thick (0.5-cm) wall. The common bile duct was dilated to 0.6 cm without sludge or calculi. The pancreas was hypoechoic, with an enlarged, 3.3-cm pancreatic head. Sonography showed dilatation of the small- and large-bowel loops, with multiple roundworms in duodenal and colonic loops. Sonography has an important role not only in the diagnosis of this uncommon condition but also in the documentation of its unusual etiologic agent.