Systemic congestion is one of the mechanisms involved in acute decompensated heart failure (ADHF). Increased intra-abdominal pressure (IAP), elicited by abdominal congestion, has been related to acute kidney injury and prognosis. Nonetheless, the link between diuretic response, surrogate markers of congestion and renal function remains poorly understood. We measured IAP in 43 patients from a non-interventional, exploratory, prospective, single center study carried out in patients admitted for ADHF. IAP was measured with a calibrated electronic manometer through a catheter inserted in the bladder. Normal IAP was defined as < 12 mmHg. At baseline, median IAP was 15 mmHg, with a reduction over the next 72 h to a median of 12 mmHg. A higher IAP at admission was associated with higher baseline blood urea (83 mg/dL [62–138] vs. 50 mg/dL [35–65]; p = 0.007) and creatinine (1.30 mg/dL vs. 0.95 mg/dL; p = 0.027), and with poorer diuretic response 72 h after admission, either measured by diuresis (14.4 mL/mg vs. 21.6 mL/mg; [p = 0.005]) or natriuresis (1.2 mEqNa/mg vs. 2.0 mEqNa/mg; [p = 0.008]). A higher incidence for 1-year all-cause mortality (45.0% vs. 16.7%; log-rank test = 0.041) was observed among those patients with IAP > 12 mmHg at 72 h. In patients with ADHF, higher IAP at admission is associated with poorer baseline renal function and impaired diuretic response. The persistence of IAP at 72 h above 12 mmHg associates to longer length of hospital stay and higher 1-year all-cause mortality.