['Anaemia may affect B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) levels, but this has not been well described in heart failure (HF) patients without the exclusion of patients with renal dysfunction.', 'To study the influence of both anaemia and renal function on BNP and NT-proBNP levels in a large group of hospitalised HF patients.', "We studied 541 patients hospitalised for HF (mean age 71+/-11 years, 62% male, and left ventricular ejection fraction 0.33+/-0.14). Of these patients, 30% (n=159) were anaemic (women: Hb<7.5 mmol/l, men: Hb<8.1 mmol/l). Of the 159 anaemic patients, 73% had renal dysfunction (eGFR<60 ml/min/1.73 m2) and of the non-anaemic patients, 57% had renal dysfunction. BNP and NT-proBNP levels were measured in all patients before discharge. In multivariable analyses both plasma haemoglobin and eGFR were independently related to the levels of BNP and NT-proBNP (standardised beta's of -0.16, -0.14 [BNP] and -0.19, -0.26 [NT-proBNP] respectively, P-values<0.01)."] Are anaemia and renal dysfunction independently associated with BNP and NT-proBNP levels in patients with heart failure?