Abstract Background: Hepatocellular carcinoma (HCC) is one of the leading causes of death from cancer world wide. Proper detection of malignant liver diseases of great value for patient management. Non invasive diagnosis of HCC depends on ultrasound (US), triphasic CT, magnetic resonance imaging (MRI), positron emission tomography (PET/CT). This study will assess the value of PET/CT in diagnosis of HCC in comparison with triphasic CT. Aim of Study: To assess the added value of PET/CT compaired with triphasic CT for improving tumor detection and ultimately modifying treatment strategies in patients with HCC. Patients and Methods: The study was carried out on forty patients for primary diagnosis and staging of HCC patients referred to the Nuclear Medicine Unit in the Radiodiagnosis Department of Ain Shams University Hospital for PET/CT assessment in the period from January 2020 till March 2021. Results: This findings showed that PET/CT is more sen-sitive than Triphasic CT in HCC diagnosis with sensitivity, specificity, PPV, and NPV of 100%, 33.3%, 89.5% and 100% respectively. Conclusion: We concluded that PET/CT is as sensitive as the triphasic CT for diagnosis of HCC.