Abstract Objective. Cirrhotic patients have an increased ratio of urinary cortisol to cortisone metabolites, indicating decreased renal 11-β-hydroxysteroid dehydrogenase type-2 activity. This suggests that cortisol - by activation of the mineralocorticoid receptor - may contribute to the abnormal sodium retention evident in cirrhosis. The aim was to elucidate the role of glucocorticoids in sodium retention in decompensated cirrhotic patients. Methods. A randomized, double-blind, placebo-controlled, crossover study was performed in nine patients with alcoholic cirrhosis of the liver. A washout interval of 14 days separated the two periods. After a basal period of 36 h, dexamethasone (0.5 mg every 6 h) or placebo was given for two days. Urine was collected for 12 h periods, and the concentrations of sodium, potassium, creatinine, cortisol and cortisol metabolites were determined. Blood samples for hemoglobin, glucose, sodium, potassium, creatinine, aldosterone and cortisol were obtained daily. Results. Dexamethasone treatment decreased S-cortisol 92.3% (82.9-93.4%) (median and range) compared with that in the basal period. Natriuresis (dexamethasone - placebo) increased 55.1 (-26.4-168.7) mmol/day (median and range). No statistically significant differences (dexamethasone - placebo) were found in changes in body weight (0.00 (-0.45-2.20) kg/day), diuresis (0.56 (-0.35-1.43) L/day) or mean arterial pressure (8.33 (-16.0-41.3) mmHg) (median and range) in reference to the preceding 24 h basal period. Conclusion. These results indicate that endogenous glucocorticoids contribute to the sodium retention in patients with alcoholic cirrhosis of the liver.