Among possible causes of a condition of immunodeficiency, we have to consider the presence of a serious chylous dysplasia, due to the great loss of proteins through the intestinal lumen. A 20-year-old male, suffered from diarrhoea (2-4 times a day), weight loss (8 kilos in 5 years), and malnutrition (hypogammaglobulinemia, hypoalbuminemia, leukocytopenia with lymphocytopenia). Accurate diagnostic assessment allowed to diagnose a protein-losing enteropathy. Conventional oil contrast lymphangiography allowed to accurately assess the case and to establish a proper therapeutic approach. The operation consisted in multiple antigravitational ligatures of dilated and incompetent chylous vessels and chylous vessel-mesenteric vein microanastomoses. Parameters concerning albumin and leukocytes normalized in 1 week after operation and remained stable with time; there were no more episodes of diarrhoea and the patient recovered weight. An accurate diagnostic assessment and above all lymphangiography allow to diagnose properly difficult cases of immunodeficiency due to intestinal protido-dispersion and to plan a correct therapeutic functional approach.