Introduction: Iron deficiency (ID) has recently been identified as a threat to patients with heart failure with reduced ejection fraction (HFrEF). This study was conducted to determine the occurrence of ID among HFrEF patients in a Malaysian tertiary hospital and its correlation between left ventricular ejection fraction (LVEF). Methods: Stable patients with LVEF less than 45% were included. Demographic data, LVEF (Simpsons) and cardiac functional status were studied, along with full blood count and iron profile. Results: 81 patients with a mean LVEF of 33.6% were recruited. 43.2% of them were NYHA class II patients, followed by 38.3% class III, 13.6% class I and 4.9% class IV patients. About 2/5 of the study population were anaemic, and of those, 48.5% were iron deficient. Majority of these anaemic patients (87.5%) had an absolute iron deficiency. Pearson’s statistical analysis showed positive correlation between ejection fraction and serum ferritin (r=0.624, p< 0.001), serum iron (r= 0.302, p