Cystic lymphangioma of the gallbladder is quite a rare tumor with only a few cases having been reported in the literature. We describe here a rare case of cystic lymphangioma of the gallbladder, which was unusual in that the patient presented with biliary pain and an abnormal liver test. Ultrasonography and computed tomography of the abdomen showed a multi-septated cystic mass in the gallbladder fossa and an adjacent compressed gallbladder. Endoscopic retrograde cholangiography showed there was no communication between the bile tract and the lesion, and there were no other abnormal findings with the exception of a laterally compressed gallbladder. After performing endoscopic sphincterotomy, a small amount of sludge was released from the bile duct. The histological findings were consistent with a cystic lymphangioma originating from the subserosal layer of the gallbladder. This unusual clinical presentation of a gallbladder cystic lymphangioma was attributed to biliary sludge, and this was induced by gallbladder dysfunction that was possibly from compression of the gallbladder due to the mass.