BACKGROUND There are different variations in the anatomy of the gallbladder. Congenital abnormalities of the gallbladder such as agenesis and hypoplasia are rare conditions and difficult to diagnose with imaging studies. Patients are usually asymptomatic or have symptoms that mimic gallstone disease. The diagnosis is often made intraoperatively and is established by histopathological examination. CASE REPORT We report a case of a 62-year-old male who had cholelithiasis symptoms and was falsely diagnosed with gallstone disease by abdominal ultrasound scan. The patient underwent an operation which revealed a rudimentary gallbladder. The histology result showed hypoplastic gallbladder tissue. CONCLUSIONS This case suggests that surgeons need to take into consideration congenital anomalies of the gallbladder intraoperatively in order to avoid any iatrogenic injury to biliary tract during a routine laparoscopic cholecystectomy. Intraoperative cholangiography can be a useful tool to avoid unnecessary surgical risky interventions.