['To evaluate the effect of iron deficiency (ID) and/or anaemia on health-related quality of life (HRQoL) in patients with chronic heart failure (CHF).', 'We undertook a post-hoc analysis of a cohort of CHF patients in a single-centre study evaluating cognitive function. At recruitment, patients provided baseline information and completed the Minnesota Living with Heart Failure questionnaire (MLHFQ) for HRQoL (higher scores reflect worse HRQoL). At the same time, blood samples were taken for serological evaluation. ID was defined as serum ferritin levels <100 ng/mL or serum ferritin <800 ng/mL with transferrin saturation <20%. Anaemia was defined as haemoglobin ≤12 g/dL. A total of 552 CHF patients were eligible for inclusion, with an average age of 72 years and 40% in NYHA class III or IV. The MLHFQ overall summary scores were 41.0 ± 24.7 among those with ID, vs. 34.4 ± 26.4 for non-ID patients (P = 0.003), indicating worse HRQoL. When adjusted for other factors associated with HRQoL, ID was significantly associated with worse MLHFQ overall summary (P = 0.008) and physical dimension scores (P = 0.002), whereas anaemia was not (both P > 0.05). Increased levels of soluble transferrin receptor were also associated with impaired HRQoL (P ≤ 0.001). Adjusting for haemoglobin and C-reactive protein, ID was more pronounced in patients with anaemia compared with those without (P < 0.001).'] Is iron deficiency a key determinant of health-related quality of life in patients with chronic heart failure regardless of anaemia status?