AIMS: Anaemia is a co-morbidity frequently seen in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF). Its presence carries adverse prognostic effects. The effects of anaemia have not been extensively investigated in patients with preserved or only mildly reduced LVEF. We sought to investigate prevalence and incidence of anaemia in patients with HF irrespective of whether reduced or preserved ejection fraction are present. In addition, we sought to study the effects of nebivolol on the development of anaemia. METHODS AND RESULTS: We analysed data from 2069 patients randomized to nebivolol or placebo in the SENIORS study, 391 (10.0%) of whom were anaemic. Anaemia was similarly common in patients with LVEF=35% and those with LVEF>35% (19.0 vs. 18.7%, P= 0.89). Anaemic patients were older, had lower diastolic blood pressure, and worse kidney function (all P< 0.05). No difference was found between patients on nebivolol or placebo with regard to the presence of anaemia. A total of 348 (16.8%) patients died during follow-up. The combined primary endpoint of all-cause mortality and cardiovascular hospital admission was reached by 687 (33.2%) patients during follow-up, 164 (23.4%) of whom were anaemic. Anaemic patients had a higher risk of reaching a primary endpoint than non-anaemics [LVEF=35%: hazard ratio (HR) 1.47, 95% confidence interval (CI) 1.18-1.82, P< 0.001; LVEF>35%: HR 1.47, 95% CI 1.09-2.00, P= 0.012]. After multivariable adjustment, haemoglobin remained an independent predictor of the primary outcome in this cohort of patients (HR 0.94 per 1 g/dL increase, 95% CI 0.89-0.99, P= 0.017). CONCLUSIONS: Anaemia is an independent predictor of death or hospitalization for cardiovascular reasons among elderly patients with chronic HF and reduced or preserved/mildly reduced LVEF. Nebivolol does not affect haemoglobin values during follow-up.