In experiments on laboratory nonlinear white mature rats, the effect of melatonin (5 mg/kg) on the morphofunctional state of kidneys under the conditions of cisplatin-induced acute kidney injury was studied. It was found that single administration of cisplatin at a dose of 6 mg/kg causes necrosis and disseminated degenerative changes of tubular cells with the development of oliguric form of toxic nephropathy, which is accompanied by a decrease in diuresis by 2.9 times, a reduction of glomerular filtration rate by 5 times, an increase in plasma creatinine level by 2.2 times, a significant proteinuria and decreased tubular reabsorption capacity. It was established that the use of melatonin in the prophylactic-therapeutic regimen demonstrates a cytoprotective effect in relation to the epitheliocytes of the renal tubules, significantly limiting the degree and prevalence of histopathological changes, and thus preventing the development of oliguria, as evidenced by a significant increase in diuresis by 1.8 times, glomerular filtration rate – by 2,6 times comparing to untreated animals; prevention of retention azotemia, hypokalemia, and significant loss of sodium ions, reducing proteinuria by 1.7 times and activating ammoniagenesis. The research results prove the prospects of the further studies to investigate the nephroprotective potential of melatonin under the conditions of renal pathology of different genesis.