The familiar diuretic spironolactone has taken on new life as a treatment for left-sided congestive heart failure. Spironolactone has been shown to decrease mortality in such patients who are New York Heart Association class IV. It can be used in addition to agents such as angiotensin-converting enzyme inhibitors and beta blockers, which also decrease mortality, and diuretics and digoxin, which are useful in treating symptoms. Spironolactone is safe, easy to use and reasonably priced. More research is necessary to determine the order and combinations of these medications in slowing the progression of this disease.