Noonan's syndrome is a rare congenital disorder that may be associated with abnormalities in the lymphatic drainage. In this case of a 21-year-old man CT after bipedal lymphangiography confirmed the diagnosis of intestinal lymphangiectasy causing protein-losing enteropathy in Noonan's syndrome by showing contrast-enhanced abnormal lymphatic vessels in the mesentery and the intestinal wall. Because of the benefit of diet in case of intestinal involvement, we recommend a thorough documentation of the lymphatic drainage with lymphangiography followed by CT, if clinical signs of lymphatic dysplasia, such as pleural effusions, lymphedema, or hypoproteinemia are present.