Sarcopenia is considered to be a poor prognostic factor for several oncological diseases; however, some promising results for lymphoma are now available. The definition of sarcopenia is mainly based upon muscle strength, quantity or quality and physical performance, but some imaging tools (such as CT) have been introduced to estimate quantitatively the muscle areas as an indirect expression of sarcopenia. Our aim was to perform a systematic review on the prognostic role of "radiological" sarcopenia in lymphoma. A comprehensive online search of PubMed/MEDLINE, Embase and Cochrane library databases was conducted up to June 2021 to find relevant articles on the prognostic role of sarcopenia in lymphoma measured by CT. In total, 25 articles with a total of 4454 patients were included. Diffuse large B-cell lymphoma was the most common lymphoma variant studied, followed by Hodgkin lymphoma. Skeletal muscle area (SMA) was defined as the parameter to distinguish between sarcopenic and nonsarcopenic lymphoma on CT scans and was usually measured at the level of the third lumbar vertebra. In the literature, different thresholds are used to define sarcopenia, related to the features of patients included in the studies. Despite this heterogeneity, in most cases, sarcopenia was demonstrated to be significantly correlated with OS and PFS. Sarcopenia measurement with CT (high dose or low dose) is a safe, accurate and precise method.