PURPOSE: To investigate whether allopurinol exerts a protective effect on kidneys by measuring new kidney injury biomarkers (NGALp, NGALu, KIM 1 and IL 18) and analysing the renal function and histology in uninephrectomised rats subjected to ischaemia-reperfusion injury. METHODS: Thirty two Wistar rats were randomly allocated to four groups: Sham (S): laparotomy; Control (C): laparotomy and ischaemia-reperfusion in the left kidney; Control Allopurinol (CA): laparotomy and allopurinol at a dose of 100mg·kg 1·d 1; and Allopurinol (A): laparotomy ischaemia-reperfusion in the left kidney and allopurinol at a dose of 100mg·kg 1·d 1. The NGALp, NGALu, KIM 1, IL 18 and creatinine levels and the kidney histology were analysed. The significance level was established as p<0.05. RESULTS: Creatinine level increased in all the groups, with A ≈ C > S ≈ CA. The NGALp, NGALu and IL 18 levels exhibited similar behaviour in all the groups. KIM 1 was higher in group A than C and showed intermediate values in groups S and CA. Severity of injury in the left kidney was greater in groups C and A compared to S and CA. CONCLUSION: Allopurinol did not exert protective or damaging effects on the kidneys of rats subjected to ischaemia-reperfusion injury.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)