Statins may be beneficial for the prevention and treatment of heart failure, as indicated by large observational studies, small prospective studies, and post hoc analyses of cardiovascular databases. Two large, prospective, controlled trials have, however, shown that rosuvastatin has neutral effects on the survival of patients with chronic heart failure. The benefits of statin treatment seem to mostly result from their ability to halt disease progression in heart failure, particularly in patients with coronary artery disease. Based on these results, statin treatment might only be useful for the prevention of heart failure, and possibly in patients with new-onset heart failure. This Review highlights data from observational data analyses as well as from the large prospective trials investigating the safety and efficacy of statins in patients with heart failure. The results from these studies and their implications for the timing of initiating statin therapy in this patient population are also discussed.