Tuberculosis (TB) is currently the world’s leading cause of infectious mortality. The complex immune response of the human body to mycobacterium tuberculosis results in a wide array of clinical manifestations, thus the clinical and radiological diagnosis are challenging. ¹⁸F-FDG-PET/CT images the whole body and provides a metabolic map of the infection, enabling clinicians to assess the disease burden. ¹⁸F-FDG-PET/CT scan is particularly useful in detecting the disease in previously unknown sites, and allows the most appropriate site of biopsy to be selected. ¹⁸F-FDG-PET/CT is also very valuable in assessing early disease response to therapy, and play an important role in cases where conventional microbiological methods are unavailable and for monitoring response to therapy in cases of undecided treatment duration such as multidrug-resistant TB or in extrapulmonary TB. High ¹⁸F-FDG up-taking focus can also be seen in clinically cured patients and in old fibrotic scarring. Thus, high uptake of ¹⁸F-FDG by PET may both represent ongoing active disease, or simply the host immune system activity that will ultimately prevail. ¹⁸F-FDG-PET/CT cannot reliably differentiate active TB lesion from malignant lesions and false positives can also be due to other infective or inflammatory conditions. ¹⁸F-FDG PET is also unable to distinguish tuberculous lymphadenitis from metastatic lymph node involvement. The lack of specificity is a limitation for ¹⁸F-FDG-PET/CT in TB management. The interpretation of ¹⁸F-FDG-PET finding must be carefully correlated with clinical data.