Background: heart is the target organ for Aldosterone, spironolactone and eplerenone (mineralocorticoid receptor antagonists) inhibits the aldosterone extraction through the heart in patients with congestive heart failure (CHF). Objective: to evaluate prognostic impact of both MRA (spironolactone and eplerenone) on heart failure and compare between both agents in incidence of side effect (gynecomastia and hyperkalemia). Patients and Methods: the study was conducted from March 2016 to September 2016 at Aswan University hospital. Our study population consisted of 100 adult patients, who were proved to have heart failure symptoms, with reduced ejection fraction heart failure divided in two groups. Group A contains 50 patients on spironolactone in addition to other anti-failure treatments according to ESC guidelines. Group B is 50 patients on eplerenone in addition to other anti-failure treatments according to ESC guidelines. Results: follow up had been done after one month for patient clinical status and serum potassium level and development of gynecomastia. Another Follow up was done after 3 months for BNP level, gynecomastia, NYHA classification and body weight. Conclusion: MRA are important line of treatment in HF patients, eplerenone and spironolactone are both have good result in improving BNP level and improving NYHA classifications and patients weight loss.