Acute kidney injury (AKI) is a rare but life-threatening complication of the administration of methotrexate (MTX) at high doses (≥1 g/m 2 ) for treatment of solid or hematological malignancies. MTX overexposure can lead to MTX-AKI, and subsequent higher risk of extra-kidney toxicities, morbidity and mortality. MTX-AKI can also lead to secondary chronic kidney disease requiring a reduced dose or contraindication for subsequent MTX infusions, thus worsening the cancer-related prognosis. Treatment of MTX-AKI is mainly preventive, combining alkaline hyperhydration, withdrawal of all nephrotoxic agents and drugs that modulate the metabolism of MTX, metabolic salvage using leucovorin (folinic acid), and close monitoring of serum MTX and creatinine concentrations. Glucarpidase (carboxypeptidase-G2), a recombinant bacterial enzyme that hydrolyzes MTX into two non-cytotoxic metabolites, should be considered for patients with MTX overexposure to prevent and lessen AKI and other potential toxicities. This article provides a comprehensive review of MTX metabolism, mechanisms and prevention of MTX-AKI, and its management.