Diuretics interfere with the sodium retention of heart failure by inhibiting the reabsorption of sodium in the renal tubes, increase urine output and decrease physical signs of fluid retention in patients with heart failure (HF). Diuretics are the only drugs used for the treatment of HF that can adequately control the fluid retention of HF. Loop diuretics, potassium-sparing agents and thiazides are used for treatment. Tolvaptan, vasopressin receptor antagonists, is a new drug and long-term clinical trials are under way to determine the role. The use of inappropriate doses of diuretics will lead to result in fluid retention, renal insufficiency with ACE inhibitors and ARBs, increase the risk of treatment with beta blockers or volume contraction, increase the risk of hypotention and diminish the response to ACE inhibitors and ARBs. Appropriate use of diuretics is important in the success of the treatment of HF.