Background: Abdominal lymphangioma is a rare benign congenital malformation of the mesenteric and/or retroperitoneal lymphatics. Clinical presentation is variable and may be misleading; therefore, complex imaging studies are necessary in the evaluation of this condition. US and CT have a major role in the correct preoperative diagnosis and provide important information regarding location, size, adjacent organ involvement, and expected complications. Objective: To evaluate the clinical and imaging findings of seven children with proven abdominal cystic lymphangioma. Materials and Methods: Clinical and imaging files of seven children with pathologically proven abdominal lymphangioma, from three university hospitals, were retrospectively evaluated. Patient's ages ranged from 1 day to 6 years (mean, 2.2 years). Symptoms and signs included evidence of inflammation, abnormal prenatal US findings, chronic abdominal pain, haemorrhage following trauma, clinical signs of intestinal obstruction, and abdominal distension with lower extremities lymphoedema. Plain films of five patients, US of six patients and CT of five patients were reviewed. Sequential imaging examinations were available in two cases. Results: Abdominal plain films showed displacement of bowel loops by a soft tissue mass in five of six patients, two of them with dilatation of small bowel loops. US revealed an abdominal multiloculated septated cystic mass in five of six cases and a single pelvic cyst in one which changed in appearance over 2 months. Ascites was present in three cases. CT demonstrated a septated cystic mass of variable sizes in all available five cases. Sequential US and CT examinations in two patients showed progressive enlargement of the masses, increase of fluid echogenicity, and thickening of walls or septa in both cases, with multiplication of septa in one case. At surgery, mesenteric lymphangioma was found in five patients and retroperitoneal lymphangioma in the other two. Conclusions: US and CT are highly sensitive in the diagnosis of abdominal lymphangioma. Our limited experience with follow-up examinations in two patients suggests that progressive enlargement, multiplication and thickening of septa and increased echogenicity of the cystic fluid are signs indicating complications demanding urgent treatment.