The administration of more than 15 L of saline over 10 days did not correct the metabolic alkalosis (plasma total CO2 35 mEq/L) of a patient with ascites secondary to ovarian carcinoma. Weight gain was more than 6 kg and urine chloride concentration remained less than 15 mEq/L. The tubular avidity for chloride and sodium which maintains metabolic alkalosis persisted in the face of saline administration, perhaps because of "ineffective" volume expansion.