Adenocarcinoma of ampulla of Vater is an uncommon malignancy with incidence of 0.5% of all gastrointestinal malignancy. Liver is the most common metastatic site, but it is unusual to occur in early stage with complete resection. Due to relative rare, detecting hepatic metastases from early stage adenocarcinoma of ampulla of Vater by F-18 FDG PET/CT is still under investigation. We present a case of early stage (T2N0M0) adenocarcinoma of ampulla of Vater, with hepatic metastases 1 year after complete resection of primary tumor. F-18 FDG PET/CT helps to confirm hepatic metastases which were equivocal on CT and MRI. Moreover, F-18 FDG PET/CT also detected an incidental rectal intramucosal adenocarinoma.The usefulness of F-18 FDG PET/CT to detect hepatic metastases from adenocarcinoma of ampulla of Vater and incidental colorectal malignancy is also evaluated.