While the use of positron emission tomography-computed tomography (PET-CT) is a standard of care in oncological practice in many developed countries, it is still limited in many low to middle income nations. To make reliable information more widely available, the IAEA convened an expert consultant group to review, based on the most recent developments of PET radiopharmaceuticals, Human Health Series No. 9, Appropriate Use of FDG-PET for the Management of Cancer Patients. This, the resulting publication, provides up to date recommendations on the optimal use of PET-CT imaging procedures in oncology. It is written for policy makers and decision makers who allocate resources dedicated to the health care system, a critical issue in the development of nuclear medicine in low and middle income countries. It will also benefit medical imaging practitioners as well as referring physicians.