Edema is referred to increase in interstitial fluid that is clinically evident. The main causes of generalized edema are heart failure, renal failure, nephrotic syndrome, glomerulonephritis and chronic liver failure. In some cases, edema is treated by management of the underlying disease. However, in some other cases edema may persist and become more severe that needs adjuvant treatments. Because use of diuretics such as furosemide and hydrochlorothiazide is not completely effective in treating severe refractory edema, use of some other diuretics is also recommended. In this double-blind clinical trial, weight and some lab data including blood urea nitrogen, serum creatinine, serum sodium, serum potassium, serum triglyceride and cholesterol of the 20 random adult patients with nephrotic syndrome who have refractory edema and normal BUN and creatinine and referred to nephrology clinic of Shiraz University of Medical Sciences will be measured; the patients should not have hypokalemia and other causes of edema such as heart failure or cirrhosis. Then the patients are divided into 2 groups with 10 members in each. The first group will be prescribed 40 mg of furosemide and 50 mg of hydrochlorothiazide and the second one will receive 250 mg of acetazolamide and 50 mg of hydrochlorothiazide daily for 1 week. Then, weight and mentioned lab data will be measured again. After that, all the patients will have 40 mg of furosemide daily for 2 weeks. Then, weight and mentioned lab data will be measured for one more time.