We report a case of intramural gallbladder hematoma mimicking gallbladder neoplasm in a 33-year-old male; bleeding was confined to the gallbladder wall without rupture into the lumen. The patient presented with sudden onset of right upper quadrant pain, with no history of abdominal trauma. The abdomen was soft, with mild tenderness over the right upper quadrant, and a positive Murphy's sign. Abdominal sonography, computed tomography, and endoscopic retrograde cholangiopancreatography all revealed the presence of a mass lesion in the gallbladder wall. Thus, a gallbladder tumor was highly suspected. Laparoscopic cholecystectomy was performed, and intramural hematoma was found intraoperatively. The cause of intramural hemorrhage was obscure.