Objetive: To describe the characteristics of Acute Kidney Injury (AKI) in hospitalized patients in a tertiary-level hospital from January to April of 2016. Material and methods: Retrospective descriptive study that included patients admitted to medical ward and Intensive Care Unit. AKI diagnosis and severity stage were established according to Kidney Disease: Improving Global Outcomes criteria. Kidney function at discharge was evaluated by estimating the glomerular filtration rate (GFR). Results: Overall frequency of AKI was 64.83%. In the medical ward, frequency was 57.06% and in ICU, 88.14%. Overall mortality was 27.45%. The proportion of patients with AKI who had anemia, diabetes and chronic kidney disease was 84.97%, 20.92% and 19.61%, respectively. According to severity stage, the overall frequency was stage 3: 46.41%, stage 1: 30.07% and stage 2: 23.53%. The most frequent categorie...