Background: Breast cancer is a major health problem resulting in high morbidity and mortality. Early diagnosis of primary and secondary lesions is crucial to optimize treatment options. Our study aimed to investigate the role of PET-CT and CT alone in detecting metastatic lesions in breast cancer patients. Result: This retrospective study showed better PET diagnostic performance in the detection of lymph nodal and lytic bony metastatic deposits with more accurate detection of the malignant nature of hepatic focal lesions and detection of activity in sclerotic bony lesions, compared with CT alone, while CT had a higher value in the localization of lesions. Hybrid PET/CT showed optimal diagnostic performance than each modality separately. Conclusion: The combination of CT and PET was a powerful diagnostic tool that is more accurate than CT alone in the detection of distant metastases.