•In Japan, the median length of heart failure hospitalization was 16 days.•Of hospitalized patients, 85% were discharged with complete decongestion.•Admission and discharge Composite Congestion Score (CCS) correlated with outcomes.•Admission CCS correlated with postdischarge outcomes even when the CCS was 0 at discharge. Congestion is a leading cause of hospitalization and a major therapeutic target in patients with heart failure (HF). Clinical practice in Japan is characterized by a long hospital stay, which facilitates more extensive decongestion during hospitalization. We herein examined the time course and prognostic impact of clinical congestion in a large contemporary Japanese cohort of HF. Peripheral edema, jugular venous pressure, and orthopnea were graded on a standardized 4-point scale (0–3) in 3787 hospitalized patients in a Japanese cohort of HF. Composite Congestion Scores (CCS) on admission and at discharge were calculated by summing individual scores. The primary outcome was a composite of all-cause death or HF hospitalization. The median admission CCS was 4 (interquartile range, 3–6). Overall, 255 patients died during the median hospitalization length of 16 days, and 1395 died or were hospitalized for HF over a median postdischarge follow-up of 396 days. The cumulative 1-year incidence of the primary outcome increased at higher tertiles of congestion on admission (32.5%, 39.3%, and 41.0% in the mild CCS ≤3, moderate CCS = 4 or 5, and severe CCS ≥6 congestion groups, respectively, log-rank P < .001). The adjusted hazard ratios of moderate and severe congestion relative to mild congestion were 1.205 (95% confidence interval CI, 1.065–1.365; P = .003) and 1.247 (95% CI, 1.103–1.410; P < .001), respectively. Among 3445 patients discharged alive, 85% had CCS of 0 (complete decongestion) and 15% had a CCS of 1 or more (residual congestion) at discharge. Although residual congestion predicted a risk of postdischarge death or HF hospitalization (adjusted hazard ratio, 1.314 1.145–1.509; P < .001), the admission CCS correlated with the risk of postdischarge death or HF hospitalization, even in the complete decongestion group. No correlation was observed for postdischarge death or HF hospitalization between residual congestion at discharge and admission CCS (P for the interaction = .316). In total, 85% of patients were discharged with complete decongestion in Japanese clinical practice. Clinical congestion, on admission and at discharge, was of prognostic value. The severity of congestion on admission was predictive of adverse outcomes, even in the absence of residual congestion. https://clinicaltrials.gov/ct2/show/NCT02334891 (NCT02334891) https://upload.umin.ac.jp/cgi–open–bin/ctr_e/ctr_view.cgi?recptno=R000017241 (UMIN000015238) Display omitted