Positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) is an accurate technique for staging and therapeutic monitoring in oncology. We evaluated our use of FDG PET in an oncology centre after our first 2500 studies, and summarise our experience of PET for the major referral indications. Optimised for clinical service, PET offers lower scanning costs and therefore improved cost-effectiveness.