Glucocorticoid administration is not recommended in patients with heart failure because of its related sodium and fluid retention. However, previous experimental and clinical studies have demonstrated that glucocorticoids can also induce a diuretic effect and improve renal function in patients with acute decompensated heart failure (ADHF) with refractory diuretic resistance. We report the case of a 65-year-old man with a known diagnosis of aortic stenosis, systolic ventricular dysfunction, and chronic obstructive pulmonary disease who was admitted for ADHF. After 3 days, during which resistance to conventional therapy was observed, intravenous methylprednisolone (60 mg/d) was added to ongoing medical treatment. Three days after the onset of glucocorticoid therapy, daily urine volume progressively increased (up to 5.8 L/d). Concurrently, signs and symptoms of congestion improved, the weight and brain natriuretic peptide plasma levels decreased (−7 kg and −46%, respectively) and glomerular filtration rate increased (+26%). Bioimpedance vector analysis showed a net reduction of fluid content (from 88.4% to 73.6% of hydration at discharge). In conclusion, this case report suggests that in a patient with ADHF and congestion resistant to diuretic therapy, glucocorticoid administration is safe and associated with improvement in congestion, neurohormonal status, and renal function. These data support the possible usefulness of glucocorticoids in this setting.