Randomized controlled trials have demonstrated the benefits of guideline-directed medical therapy in the outpatient setting for treatment of chronic heart failure. However, the benefits of continuation (or discontinuation) of major chronic heart failure therapies when treating acute heart failure during hospitalization are less clear. Real and anticipated worsening renal function, hyperkalemia and hypotension are the three major reasons for discontinuation of renin-angiotensin-aldosterone system inhibitors during hospitalization, and a failure to resume renin-angiotensin-aldosterone system inhibitors before discharge could worsen cardiovascular outcomes. Available data, mostly observational, shows that continuation or initiation of renin-angiotensin-aldosterone system inhibitors appears efficacious, safe, and well tolerated in majority of acute heart failure patients during hospitalization. Worsening renal function portends poor prognosis only if associated with congestion in acute heart failure, and clinicians should not de-escalate diuretic therapy routinely for worsening renal function.