Background: Studies on clinical features, treatment and prognosis of patients with congestive heart failure (CHF) and preserved left ventricular ejection fraction (LVEF) are few and their results frequently conflicting. Aims: To investigate the characteristics and long term prognosis of patients with CHF and preserved ( 45%) LVEF. Methods and Results: We conducted a prospective multicentre study with 4720 patients attended in 62 heart failure clinics from 1999 to 2003 in Spain (BADAPIC registry). LVEF was preserved in 30% patients. Age, female gender, prevalence of atrial fibrillation, hypertension and non-ischaemic cardiopathy were all significantly greater in patients with preserved LVEF. Mean follow-up was 40±12 months. Mortality and other cardiovascular complication rates during follow up were similar in both groups. On multivariate analysis ejection fraction was not an independent predictor for mortality. Survival at one and five years was similar in both groups (79% and 59% for patients with preserved LVEF and 78% and 57% for those with reduced LVEF, respectively). Conclusions: In the BADAPIC registry, a high percentage of heart failure patients had preserved LVEF. Although clinical differences were seen between groups, morbidity and mortality were similar in both groups.