AimsInpatients with heart failure and renal impairment have poor outcomes and variable quality of care. We investigate treatment practice and outcomes in an unselected real‐world cohort using historical creatinine measurements.Methods and resultsAdmissions between 1/4/2013 and 30/4/2015 diagnosed at discharge with heart failure were retrospectively analysed. Stages of chronic kidney disease (CKD) and acute kidney injury (AKI) were calculated from creatinine at discharge and 3–12 months before admission. We identified 1056 admissions of 851 patients (mean age 76 years, 56% Caucasian, 36% with diabetes mellitus, 54% with ischaemic heart disease, and 57% with valvular heart disease). CKD was common; 36%—Stage 3a/b, 11%—Stage 4/5; patients were older, more often diabetic, with higher potassium, lower haemoglobin, and more oedema but similar prevalence of left ventricular systolic dysfunction (LVSD) compared patients with Stages 0–2. AKI was present in 17.0% (10.4%—Stage 1, 3.7%—Stage 2, and 2.9%—Stage 3); these had higher potassium and lower haemoglobin than patients with no AKI. Length of stay was longer in Stage 4/5 CKD [11 days; P = 0.008] and AKI [13 days; P = 0.006]. Mortality was higher with Stage 4/5 CKD (13.8% compared with 7.7% for Stages 0–2 CKD (P = 0.036)] and increased with AKI (5%—no AKI, 20.9%—Stage 1, 35.9%—Stage 2, and 48.4%—Stage 3; P < 0.001). Adjusted for age, diabetes, and LVSD, both AKI and Stage 4/5 CKD were independent predictors of in‐hospital mortality. In survivors with LVSD, the discharge prescription of angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers decreased with progressive CKD, [84%—no‐mild, 59%—moderate, and 36%—severe CKD; P < 0.001]; this was not purely explained by hyperkalaemia.ConclusionsInpatients with heart failure and renal impairment, acute and chronic, failed to receive recommended therapy and had poor outcomes.