Objective To investigate the value of MRI and CT findings in the diagnosis of abdominal cystic lymphangioma in children. Methods A total of 19 children with abdominal cystic lymphangioma diagnosed in the hospital during the period from August 2012 to August 2017 were selected. Their MRI and CT image features before operation were retrospectively analyzed. Results Postoperative pathological examination showed that tumors in 11 of the 19 children were located in the mesentery, 5 in the posterior peritoneum, 2 in the larger omental sac and 1 in both adrenal glands. CT images showed that the inner walls of lesions were thin and the inner shape was irregular. The cystic thinwall masses were single-cavity or multi-cavity, with lesions surrounding the blood vessels, stomach wall and intestinal lumen. There was septation between some lesions and showed water-like density. After injection of contrast agents, the wall and the septum were slightly enhanced, and the capsule was not enhanced inside. MRI images showed longer T1 and T2 signals at the diseased site. Conclusion MRI and CT can clearly show the main position, range and internal characteristics of abdominal cystic lymphangioma, reflect the specific conditions of the patient, which is of great significance for preoperative diagnosis and surgery. The two imaging examinations can be used for the diagnosis of abdominal cystic lymphangioma in children and helps doctors diagnose and formulate scientific treatment plans.