This e-learning module presents the revised and updated guidelines in IAEA Human Health Series No. 45 –?PET–CT for the Management of Cancer Patients: a Review of the Existing Evidence. These guidelines were created through consensus based on current evidence, to make health care providers and policy makers aware of the value and the recommended use of PET–CT in the management of cancer patients. This module provides a good overview of all the common indications of PET–CT in clinical oncology.