Introduction: Acute tubulointerstitial nephritis (ATIN) is a rare entity in the pediatric age. It is defined by the infiltration of the renal parenchyma by mononuclear and/or polynuclear cells with secondary involvement of the tubules, without glomerular injury. It can be triggered by infections or immunological diseases, drugs like NSAIDs or be of idiopathic origin. Objective: To raise awareness among pediatricians about the prescription of NSAIDs, especially to patients of less than a year old, since they can provoke renal damage. Case report: A ten month old child, with no nephrological antecedents of interest, was transferred to our hospital due to acute renal failure stage 3 KDIGO 2012. The three previous days received treatment with amoxicillin and ibuprofen for acute otitis media. Physical examination revealed mild eyelid edema with normal blood pressure. In the urine analysis, there were non-nephrotic proteinuria with tubular component, microhematuria and leukocyturia. Renal ultrasound showed no abnormalities. ATIN was suspected and so the antibiotic was changed to intravenous cefotaxime and ibuprofen was discontinued, opting for conservative management of acute renal damage. There was an increase in the number of creatinine up to 4.14 mg/dL and eosinophilia, with the immunological study being negative. Treatment with methylprednisolone was initiated, achieving normalization of renal function. Discussion: NTIA can be produced by any medication through an idiosyncratic immune reaction. Among the responsible drugs, there are ones commonly used in the pediatric age, such as NSAIDs. Therefore, the pediatricians should pay special attention during prescriptions and have a high diagnostic suspicion of this disease.