We report 18 F-FDG PET/CT appearances of intracholecystic papillary neoplasm (ICPN) in the gallbladder neck and duct of a 74-year-old woman with a history of hepatitis B cirrhosis. The lesion presented with a large and sessile soft mass in the neck and duct of gallbladder with obvious glucose metabolism on PET/CT images, which was confirmed pathologically as ICPN (gastric foveolar type) with high-grade intraepithelial neoplasia. ICPN localized in the gallbladder neck and duct is extremely rare, and is easily misdiagnosed as gallbladder carcinoma. Our report aids in the application of PET/CT in the differential diagnosis of ICPN and guiding early surgery.