FOLFIRINOX chemotherapy is recommended as first-line treatment for metastatic pancreatic ductal adenocarcinoma (mPDAC). Its effectiveness was well documented in clinical trials, but responses were mostly partial. Complete responses (CR) assessed by CT scan have been rarely reported in the literature. In a 56-year-old man with poorly differentiated mPDAC, treatment with FOLFIRINOX achieved a long complete metabolic response lasting 23 months. Response was assessed using LAFOV FDG-PET/CT. This case highlights the role of the latest generation digital FDG-PET/CT system in the treatment of solid cancers.