This is a placebo-controlled, double-blind and randomized clinical trial that will include patients with symptomatic stable chronic heart failure (New York Heart Association Functional Class II or III), with diagnosis of iron deficiency (ferritin <100 ng / dL or ferritin between 100 - 300 ng / dL and transferrin saturation <20%) followed in an outpatient clinic. The enrolled patients (n = 36) will be randomly allocated in the ratio 2:1 to treatment with 60 mg of elemental iron orally (n = 24) or placebo administration (n = 12), 3 times daily for 4 months. The primary outcome investigated will be an increase of the transferrin saturation ≥ 10 percentage points between baseline and after the intervention. Secondary outcomes of the study will be the change in iron stores, red blood cell indices, neurohumoral activation, left ventricular systolic function, functional capacity, mechanoreflex activity, and quality life score.