Adenoma is the most frequent type of gallbladder (GB) neoplasm; however, GB neoplasms are unusual and unsuspected diagnoses in childhood. The average patient age is 50.5+/-16.3 years. We present a case of tubulopapillary adenoma of the gallbladder in a 3-year-old girl. She was admitted to the hospital with a 6-month history of abdominal pain and nausea and vomiting. Ultrasonography (USG) revealed an echogenic soft tissue lesion in the lumen of the GB. She underwent cholecystectomy. A tubulopapillary adenoma and adenomatous hyperplasia of the GB were diagnosed histologically. According to the literature, this is the youngest patient found to have gallbladder adenoma.