18F‐fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is now an integral part of lymphoma staging and management. Because of its greater accuracy compared with CT alone, PET/CT is currently routinely performed for staging and for response assessment at the end of treatment in the vast majority of FDG‐avid lymphomas and is the cornerstone of response classification for these lymphomas according to the Lugano classification. Interim PET/CT, typically performed after 2 to 4 of 6 to 8 chemotherapy/chemoimmunotherapy cycles with or without radiation, is commonly performed for prognostication and potential treatment escalation or de‐escalation early in the course of therapy, a concept known as response‐adapted or risk‐adapted treatment. Quantitative PET is an area of growing interest. Metrics, such as the standardized uptake value, changes (Δ) in the standardized uptake value, metabolic tumor volume, and total lesion glycolysis, are being investigated as more reproducible and potentially more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value, emphasizing the need for more specific molecular probes. This review highlights the most relevant applications of PET/CT in Hodgkin and B‐cell non‐Hodgkin lymphoma, its strengths and limitations, as well as recent efforts at implementing PET/CT‐based metrics as promising tools for precision medicine. This review highlights the most relevant applications of positron emission tomography/computed tomography in lymphoma, their strengths and limitations, and recent efforts at implementing positron emission tomography‐based and computed tomography‐based metrics as potential tools of precision medicine in lymphoma.