We present the case of a patient with abdominal pain, in which gallbladder perforation was detected by contrast-enhanced ultrasound. A 90-year-old patient presented to the emergency department with a complaint of acute abdominal pain and vomiting. An abdominal ultrasound revealed a thickened gallbladder wall and small amounts of perihepatic fluid. Because these findings were suspicious for gallbladder perforation and contrast-enhanced computed tomography could not be performed because of a history of monoclonal gammopathy, a contrast-enhanced ultrasound scan was performed. After the administration of 2.5 mL of SonoVue (Bracco, Milan, Italy), a defect of the gallbladder wall was detected. The patient underwent laparotomy, on which the diagnosis of gallbladder perforation was confirmed.