This article reviews the literature on breast imaging with [18F]fluorodeoxyglucose positron emission tomography (FDG PET). In clinical applications, there is currently no defined role for detecting primary breast cancer. The limited sensitivity of FDG PET does not allow the exclusion of malignancy, in particular small breast carcinomas, micrometastases and small, tumour infiltrated lymph nodes. However, in advanced stages, PET accurately determines the extent of disease, including the loco-regional lymph node status. Furthermore, whole-body PET imaging promises a high diagnostic accuracy for detecting recurrent or metastatic breast carcinoma. Future clinical applications may include monitoring therapeutic effects.