Intra-abdominal and retroperitoneal lymphangiomas are a rare, congenital malformations of the lymphatics, which are found predominantly in children. The aim of this study is to evaluate the clinical features of this tumor, highlighting the differences in adults and pediatric patients. We also evaluate the preoperative diagnosis, radiological features, surgical treatment, and outcome of this rare condition. Between 1990 and 2004, 14 patients who underwent surgical resection of an intra-abdominal lymphangioma were reviewed retrospectively. There were five pediatric patients between fetal age and 17 years of age and nine adults between 31 and 62 years of age. Overall, females outnumbered males in the series, with a male-to-female ratio of 3:4. However, males predominated in the pediatric age group with a male-to-female ratio of 1.5:1. The clinical presentation of children was more acute ranging from 3 days to 2 months. In adults, four patients were asymptomatic, and the remaining five had symptom duration ranging from 2 weeks to a year. The lymphangiomas occurred in the mesentery (n = 4), retroperitoneum (n = 4), omentum (n = 3), pancreas (n = 2), and spleen (n = 1). All the patients underwent total surgical resection with or without organ resection, and there were no recurrences at a median follow-up of 2 years (range; 3 months--13 years). This series demonstrates that abdominal lymphangiomas have a male preponderance and present more acutely in pediatric patients, whereas in adults, female patients predominate and the history is more chronic.