Abstract: The invention relates to a reliable, easy-to-implement non-invasive diagnostic method for detecting early acute kidney injury by measuring the concentration of a biomarker in urine samples, said biomarker being selected from heat shock proteins of the 70 KDa family. More specifically, the invention relates to the identification of heat shock protein 72, whereby said biomarker is identified by means of ELISA and Western blot or by means of the level of RNAm using real-time RT-PCR. The invention helps to solve the current problem that exists in medicine whereby it is not possible to detect acute renal failure in the early stages or the severity of the renal damage in order to treat the patient in a timely manner with an effective therapy.