Findings are reported in four cases of chyluria; in three instances this was due to filariasis. Lymphangiography was carried out on two patients whose proteinuria was investigated further. The findings are compared with those of similar studies in the nephrotic syndrome. Although orally administered lipid has been shown to enter chylous urine relatively rapidly, there is a delay in the appearance of intravenously injected labelled proteins. Results of the present studies suggest the existence of an indirect pathway for the passage of plasma proteins into abdominal lymph, and that low-density-lipoprotein synthesized in the liver, or possibly in the gut wall, does not reach the systemic circulation by way of the chyle. 1