Objective To investigate the findings and diagnostic value of computerized tomography (CT) in head and neck lymphatic malformation (LM) of children.Methods The CT data of 57 cases of head and neck LMs confirmed by surgery and pathology from 2016 to 2021 were analyzed retrospectively.Results Forty-one cases (71.9%) were under 2 years old. The lesions were located on the left in 26 cases, on the right in 26 and on both sides in 5, including neck and parapharyngeal mass in 26 cases, head and face mass in 8, and mass across the head, neck or mediastinum in 23. The clinical manifestations were painless mass (n=53), facial changes (n=25), laryngeal wheezing, dyspnea or dysphagia (n=7). The above symptoms could occur alone or simultaneously. The mass was single chamber type in 25 cases and multi-chamber type in 32. Intratumoral hemorrhage was found in 30 cases. LM was diagnosed by CT in 55 cases with a positive rate of 96.5% (55/57). CT findings included single chamber or multi chamber, round, irregular and lobulated low-density or equal density shadows, creeping along the tissue gap with clear or unclear boundary. In some patients, separation shadow was observed in the capsule with unenhanced capsule content and enhanced fibrous separation and capsule wall in point, strip, cord and grid shape after enhancement. When combined with infection or bleeding, the CT value got increased, and the liquid-liquid level was visible at the same time in some patients.Conclusion With advantages of clear display of the mass location, size and range, as well as certain characteristic manifestations, CT is of great value for diagnosis and treatment of head and neck LM.