Three well-controlled epidemiology studies in the U.S. have reported that 40% of incident congestive heart failure (CHF) cases and 50% to 60% of prevalent CHF cases occur in the setting of preserved systolic function. This condition has been termed "diastolic heart failure" (DHF). Despite minor differences in the types of populations examined, these community-based studies have established DHF as a major health problem in the U.S., particularly among the elderly. Although extensive data are available concerning the natural history of CHF associated with reduced systolic dysfunction (systolic heart failure; SHF), the natural history of DHF is not well-characterized. Indeed, it remains unclear whether patients with DHF share the grim prognosis described for patients with SHF. In this review we examine the available studies comparing survival observed in patients with DHF to that observed in patients with SHF. Although there are insufficient data at present to make definitive conclusions, careful examination of the available studies raises the possibility that the natural history of patients with DHF may not be different from that observed in patients with CHF and reduced systolic function.