AIM: To determine the additional value of FDG-PET-CT as compared to conventional staging (CS) in high-risk breast cancer patients. PATIENTS AND METHODS: Thirty-one high-risk breast cancer patients, 14 of whom had recurrent breast cancer, were included in this study, which took place between June 2005 and March 2008. None of the patients had clinical signs of distant metastases. FDG-PET-CT scanning was added to CS, which consisted of a chest x-ray, liver ultrasonography or CT, and bone scintigraphy. Median follow-up was 17 months (6-41 months). FDG-PET-CT was considered to have additional value to CS if it led to a change in treatment plan or if it made additional examinations to confirm or deny findings on CS unnecessary. RESULTS: FDG-PET-CT was considered to have additional value to CS in 13 patients (42% [95% CI: 23-61]). In five patients (16% [95% CI: 1-31]), FDG-PET-CT led to a change in treatment plan by identifying nodal metastases in the internal mammary chain (IMC; N = 3) or in the mediastinum (N = 2). In nine patients (29% [95% CI: 11-47]), FDG-PET-CT would have prevented the need for additional examinations; in seven of these nine patients, distant metastases were suggested in bone or liver on CS, but these did not show FDG uptake. CONCLUSIONS: FDG-PET-CT was found to have additional value to CS in 42% of the patients. To optimize cost-effectiveness, the main challenge now is to improve the selection of patients in whom FDG-PET-CT has additional value to CS.