Sixteen patients with a pericholecystic abscess were classified into three groups according to the sonographic findings: Nine patients had an abscess in the gallbladder bed, three in an intramural location in the gallbladder, and four in an intraperitoneal cavity. In the gallbladder bed group, six patients with a localized abscess responded well to conservative therapy, followed by an elective operation. Two patients with a complicated abscess were initially treated with ultrasonically (US) guided percutaneous transhepatic gallbladder drainage and then with percutaneous transhepatic aspiration of the liver abscess, followed by an elective operation. A patient with a communicating abscess underwent an elective operation because the abscess completely disappeared after percutaneous transhepatic abscess drainage under US guidance. One of the three patients with an intramural abscess needed an immediate operation, and the other two were treated conservatively, followed by an elective operation. All four patients with an intraperitoneal abscess needed an emergency operation. Because each type of abscess received differing and successful treatments, the authors' method of classification of US findings seemed to provide a useful way to select the specific therapeutic procedure to achieve optimal results.