A 26-year-old male patient with a history of chronic peripheral lymphedema, yellowish coloured slow growing nails and pleural effusions since early childhood is described. After 23 years he developed a chylous ascites and scintigraphy with technetium-99m labeled albumin clearly demonstrated a diffuse protein loss involving the whole jejunum and ileum. Subsequent jejunal and duodenal biopsies showed the typical histological findings of intestinal lymphangiectasia thereby confirming a diffuse intestinal lymphatic damage. In addition to the gastrointestional symptoms the patient developed a pericardial effusion diagnosed by echocardiographic imaging. Dietary treatment with middle chained triglycerides and intravenous human albumin supplementation was followed by the reduction of the ascites and improvement of the peripheral lymphedema. To our knowledge this is the first description of the yellow nail syndrome associated with a diffuse lymphangiectasia involving the whole small bowel.