Rationale: Ectopic thyroid is most common in the tongue. Here we reported a rare case of thyroid tissue located in the gallbladder wall, accompanied with adenoma and a cyst lined with pseudostratified ciliated columnar epithelium in the neck region of gallbladder neck.Patient concerns: A 39-year-old female presented with recurrent upper abdominal pain and radiating back pain.Diagnoses: Based on ultrasonography, gallbladder polyps and calculous cholecystitis were suspected.Interventions: The patient was treated by laparoscopic cholecystectomy, and thyroid tissue located in the gallbladder wall was found. Histopathological examination showed no features of papillary thyroid neoplasm.Outcomes: The patient had no thyroid nodules or suspicious enlarged lymph nodes, and no other symptoms or complications by follow-up for 2.5 years up to September 2019.Lessons: We should pay attention to the rare location of ectopic thyroid tissue in the gallbladder and rule out primary thyroid malignancy to avoid unnecessary overtreatment.