Congenital anomalies of the gallbladder are rare and can be accompanied by other malformations of the biliary or vascular tree. Being difficult to diagnose during routine preoperative studies, these anomalies can provide surgeons with an unusual surprise during laparoscopic surgery. The presence of any congenital anomaly or the mere suspicion of its existence demands that we exercise surgical prudence, limit the use of electrocoagulation, and ensure that no structure be divided until a clear picture of the bile ducts and blood vessels is obtained. If necessary, perform intraoperative cholangiography to further define the biliary system. However, if the case remains unclear, or if laparoscopy does not provide enough information, open surgery should be considered before undesirable complications occur.