Acute kidney injury (AKI) is a significant health issue affecting millions and causing substantial morbidity and mortality. In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) published the first international, multidisciplinary clinical practice guideline for AKI, covering definition, risk assessment, evaluation, prevention, and treatment. This review summarizes key aspects of the guideline, including definition and staging of AKI, evaluation, and nondialytic management. The guideline is based on systematic reviews of relevant trials and follows the Grading of Recommendations Assessment, Development and Evaluation approach. Key recommendations include defining AKI by changes in serum creatinine (SCr) or urine output, stratifying patients for risk based on exposures and susceptibilities, and managing AKI according to its stage and cause. Fluid resuscitation with isotonic crystalloids is recommended over colloids, and vasopressors are suggested for patients with vasomotor shock. Nutritional management should aim for a total energy intake of 20 to 30 kcal/kg/day, and protein intake should be avoided only if necessary. Diuretics and vasodilators like dopamine, fenoldopam, and natriuretic peptides are generally not recommended for preventing or treating AKI. The guideline also emphasizes the importance of avoiding nephrotoxins such as aminoglycosides and amphotericin B.Acute kidney injury (AKI) is a significant health issue affecting millions and causing substantial morbidity and mortality. In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) published the first international, multidisciplinary clinical practice guideline for AKI, covering definition, risk assessment, evaluation, prevention, and treatment. This review summarizes key aspects of the guideline, including definition and staging of AKI, evaluation, and nondialytic management. The guideline is based on systematic reviews of relevant trials and follows the Grading of Recommendations Assessment, Development and Evaluation approach. Key recommendations include defining AKI by changes in serum creatinine (SCr) or urine output, stratifying patients for risk based on exposures and susceptibilities, and managing AKI according to its stage and cause. Fluid resuscitation with isotonic crystalloids is recommended over colloids, and vasopressors are suggested for patients with vasomotor shock. Nutritional management should aim for a total energy intake of 20 to 30 kcal/kg/day, and protein intake should be avoided only if necessary. Diuretics and vasodilators like dopamine, fenoldopam, and natriuretic peptides are generally not recommended for preventing or treating AKI. The guideline also emphasizes the importance of avoiding nephrotoxins such as aminoglycosides and amphotericin B.