Tetanus is an acute infectious disease caused by neurotoxins produced by Clostridium tetani, an anaerobic sporulated gram-positive bacillus. The infection occurs through superficial or deep wounds used as spore entry ports for contact with the continuity solution in the skin and mucosa. The action of Clostridium tetani in the body occurs through the release of exotoxins such as tetanospasmin, also known as tetanus toxin, which, due to its action of inhibiting neurotransmitter release, is responsible for the clinical manifestations of the infection, according to the class and the location of affected cells. The disease progresses in the cephalocaudal direction, with initial involvement of the head and neck muscles, until symptoms are completely widespread. Facial muscle hypertonia gives the patient characteristic expressions of the disease, also known as tetanus face. As the infection progresses, the involvement of the thoracic, abdominal and diaphragmatic muscles can lead to asphyxia, cyanosis, and respiratory failure. Acute kidney injury (AKI) in tetanus infection is common, early, and associated with increased mortality, but its pathophysiology is not yet completely understood. Some factors have been studied as possible causes of AKI, such as autonomic dysfunction, rhabdomyolysis, use of nephrotoxic medications, sepsis, mechanical ventilation complications, dehydration, and changes in renal blood circulation, secondary to catecholamine surges.