Acute kidney injury (AKI) is a common and serious complication of ST-elevation myocardial infarction (STEMI). AKI and chronic kidney disease (CKD) are highly heterogeneous, leaving a wide gap between them. Therefore, the term acute kidney disease (AKD) was implemented, describing prolonged renal injury between 7 and 90 days. We aimed to evaluate the prevalence and predictors of AKD among STEMI patients. This retrospective observational study included 2940 consecutive patients admitted with STEMI between 2008 and 2022. Renal function was assessed upon admission and routinely thereafter. Renal outcomes were evaluated according to KDIGO criteria, with AKD defined as persistent renal injury of between 7 and 90 days. Two hundred and fifty-two subjects with STEMI and AKI were included; of them, 117 (46%) developed AKD. Among baseline CKD patients, higher rates of AKD were observed (60% vs. 46%). KDIGO index ≥ 2 was an independent predictor for AKD in in subjects without baseline CKD (AOR 2.63, 95% CI 1.07-6.53). In subjects with baseline CKD, older age and higher creatinine were independent predictors for AKD. Subjects with AKD had a higher 1-year mortality rate (HR 3.39, 95% CI 1.71-6.72, p < 0.01). This trend was mainly driven by the CKD subpopulation where higher mortality rates for AKD on CKD were observed (HR 5.26, 95% CI 1.83-15.1, p < 0.01). AKD is common among STEMI patients with AKI. The presence of CKD and higher KDIGO stage should prompt strict monitoring for early diagnosis, treatment, and prevention of renal function deterioration.