A 38-year-old woman was admitted due to lymphangioleiomyomatosis (LAM)-associated massive chylous ascites and progressive cachexia. She was incidentally diagnosed to have ascites during her regular physical check-up two years previously and LAM was revealed as its underlying cause. Periodic paracentesis was required to ameliorate ascites-associated symptoms, but resulted in lymphocytopenia, malnutrition, and deterioration of general status. Ascites was refractory to diuretics and fat-restricted diet. Peritoneovenous shunt (Denver shunt) was placed and thereafter ascites has been managed successfully without any complications for one year after the placement. Peritoneovenous shunt should be considered in LAM patients whose chylous ascites can not be managed with conservative treatments.