Abstract Aims Iron deficiency (ID) is a frequent finding in patients with chronic and acute heart failure (AHF) along the full spectrum of left ventricular ejection fraction (LVEF). Iron deficiency has been related to ventricular systolic dysfunction, but its role in right ventricular function has not been evaluated. We sought to evaluate whether ID identifies patients with greater right ventricular dysfunction in the setting of AHF. Methods and results We prospectively included 903 patients admitted with AHF. Right systolic function was evaluated by tricuspid annular plane systolic excursion (TAPSE) and the ratio TAPSE/pulmonary artery systolic pressure (TAPSE/PASP). Iron deficiency was defined, according to European Society of Cardiology criteria, as serum ferritin <100 mg/dL (absolute ID) or ferritin 100–299 mg/dL and transferrin saturation (TSAT) <20% (functional ID). The relationships among the exposures with right ventricular systolic function were evaluated by multivariate linear regression analyses. The mean age of the sample was 74.3 ± 10.6 years, 441 (48.8%) were female, 471 (52.2%) exhibited heart failure with preserved ejection fraction, and 677 (75.0%) showed ID. The mean LVEF, TAPSE, and TAPSE/PASP were 49 ± 15%, 18.6 ± 3.9 mm, and 0.45 ± 0.18, respectively. The median (interquartile range) amino-terminal pro-brain natriuretic peptide was 4015 (1807–8775) pg/mL. In a multivariable setting, lower TSAT and ferritin were independently associated with lower TAPSE (P < 0.05 for both comparisons). Transferrin saturation (P = 0.017), and not ferritin (P = 0.633), was independently associated with TAPSE/PASP. Conclusion In AHF, proxies of ID were associated with right ventricular dysfunction. Further studies should confirm these findings and evaluate the pathophysiological facts behind this association.