Studies have shown that patients with compensated heart failure (HF) receiving high diuretic doses associated with normal sodium diet and fluid intake restrictions demonstrated significant reductions in readmissions and mortality compared with those who received low-sodium diets, and over a 6-month observation period, a reduction in neurohormonal activation was also observed. The aim of this study was to evaluate the effects of different sodium diets associated with different diuretic doses and different levels of fluid intake on hospital readmissions and neurohormonal changes after 6-month follow-up in patients with compensated HF. Four hundred ten consecutive patients with compensated HF (New York Heart Association class II to IV) aged 53 to 86 years, with ejection fractions <35% and serum creatinine <2 mg/dl, were randomized into 8 groups: group A (n = 52): 1,000 ml/day of fluid intake, 120 mmol/day, and 250 mg furosemide twice daily; group B (n = 51): 1,000 ml/day of fluid intake, 120 mmol/day, and 125 mg furosemide twice daily; group C (n = 51): 1,000 ml/day fluid intake, 80 mmol/day, and 250 mg furosemide twice daily; group D (n = 51): 1,000 ml/day fluid intake, 80 mmol/day, and 125 mg furosemide twice daily; group E (n = 52): 2,000 ml/day fluid intake, 120 mmol/day, and 250 mg furosemide twice daily; group F (n = 50): 2,000 ml/day fluid intake, 120 mmol/day, and 125 mg furosemide twice daily; group G (n = 52): 2,000 ml/day fluid intake, 80 mmol/day, and 250 mg furosemide twice daily; and group H (n = 51): 2,000 ml/day fluid intake, 80 mmol/day, and 125 mg furosemide twice daily. All patients received the treatments >or=30 days after discharge and for 180 days afterward. Signs of HF, body weight, blood pressure, heart rate, laboratory parameters, electrocardiograms, echocardiograms, brain natriuretic peptide, aldosterone, and plasma renin activity were examined at baseline and 180 days later. Group A showed the best results, with a significant reduction (p <0.001) in readmissions, brain natriuretic peptide, aldosterone, and plasma renin activity compared with the other groups during follow-up (p <0.001). In conclusion, these data suggest that the combination of a normal-sodium diet with high diuretic doses and fluid intake restriction, compared with different combinations of sodium diets with more modest fluid intake restrictions and conventional diuretic doses, leads to reductions in readmissions, neurohormonal activation, and renal dysfunction.