Objective To explore the clinical characteristics, in-hospital outcomes, and short-term survival of patients with acute kidney injury (AKI) in a large non-surgical cardiac intensive care unit (ICCU) in China. Methods Patients who had been admitted to the ICCU of the Department of Cardiology, West China Hospital of Sichuan University between June 2016 and May 2017 were retrospectively included. The diagnosis and staging of AKI were based on the Kidney Disease: Improving Global Outcomes criteria. The in-hospital outcomes were the composite of all-cause death or discharge against medical advice under extremely critical conditions. Patients without in-hospital composite outcomes were followed up to determine whether all-cause death occurred during the study period. The association of AKI with in-hospital composite outcomes or short-term survival was analyzed. Normally distributed quantitative data were expressed as mean±standard deviation, and non-normally distributed quantitative data were expressed as median (lower quartile, upper quartile). Results This study included 2083 patients, with an average age of (65.5±14.6) years old, and 681 (32.7%) were women. The prevalence rate of AKI was 15.0% (312/2083) (stage 1: 6.9%; stage 2: 4.9%; stage 3: 3.2%; respectively). Compared with patients without AKI, patients with AKI were older [(68.9±14.3) vs. (64.9±14.6) years old, P<0.001], had a higher Charles Comorbidity Index [4.0 (3.0, 6.0) vs. 2.0 (1.0, 3.0), P<0.001] and a greater Oxford Acute Illness Severity Score [32.0 (24.0, 41.2) vs. 21.0 (16.0, 26.0), P<0.001]. The incidence of in-hospital composite endpoint events was 8.4% (174/2083). Multiple logistic regression analysis showed that as the AKI stage increased, the risk of in-hospital composite endpoint events was higher [AKI stage 1 vs. no AKI: odds ratio (OR)=1.13, 95% confidence interval (CI) (0.57, 2.24); AKI stage 2 vs. no AKI: OR=2.21, 95%CI (1.08, 4.51); AKI stage 3 vs. no AKI: OR=10.88, 95%CI (4.50, 26.34); P for trend<0.001]. The patients without in-hospital composite endpoint events were followed up for a median time of 13.5 (10.7, 16.6) months, and the all-cause mortality rate was 5.5% (105/1909). Multiple Cox regression analysis showed that AKI was independently associated with all-cause death [hazard ratio=2.27, 95%CI (1.40, 3.69), P<0.001]. Conclusions AKI is common in the large ICCU in China and is more likely to occur in older patients who have more significant chronic illness complexity and acute illness severity. Moreover, AKI is independently associated with the in-hospital composite endpoint events and short-term survival.