18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT) is a non-invasive method for visualization of focally increased metabolism in the presence of discrete morphological changes. Based on a systematic review of current literature, PET/CT cannot be recommended as a primary diagnostic procedure in breast cancer; but it has the potential to be useful for the detection of distant metastases and for monitoring response to chemotherapy in breast cancer patients. PET/CT should still be regarded as a supplement to conventional diagnostic procedures such as CT and MRI.