Background Extrahepatic metastases and proper staging of HCC are mandatory for proper assessment of the disease process and its exact extent. Subsequently, clinicians can put precise management and treatment strategies for patients with metastatic HCC. 18FFDG PET/CT is one of the best imaging modalities for the proper detection of metastases and staging. It can provide both functional information and high contrast resolution of CT. Results On comparison between 18F FDG PET/CT and triphasic CT regarding metastases PET/CT showed greater sensitivity (92.3%) and specificity (84.4%), than triphasic CT (51.3%), (81/3%), and (76.9%), respectively. PET/CT revealed that the SUV max cutoff point for diagnosis of HCC was > 3.PET/CT revealed an SUV max cutoff point of > 5.57 for predicting that HCC has extrahepatic metastases. PET/CT revealed an SUV max cutoff point of > 3.35 for differentiating between metastatic and nonmetastatic lesions. Conclusions PET/CT combines the advantages of the excellent functional information provided by PET and the contrast resolution of CT. It increases the rate of detection of extrahepatic metastases, so it is more sensitive than triphasic CT in the staging of HCC. Using the standard uptake value proved to be efficient in HCC diagnosis and staging being more related to the functional activity of the tumor cells.