Acute tubulointerstitial nephritis (TIN) is responsible for nearly 10% of acute renal failure (ARF) cases in children. It is mostly drug-induced, but in a few cases viruses are involved, probably by an indirect mechanism. An immune-competent 13-month-old boy was admitted to the intensive care unit for severe ARF with anuria in a context of fever, cough, and rhinorrhea lasting 1 week. The kidney biopsy performed early brought out tubulointerstitial damage with mild infiltrate of lymphocytes, without any signs of necrosis. There were no virus inclusion bodies, no interstitial hemorrhage, and no glomerular or vascular damage. Other causes of TIN were excluded: there was no biological argument for an immunological, immune, or drug-induced cause. Adenovirus (ADV) and respiratory syncytial virus (RSV) were positive in respiratory multiplex polymerase chain reaction (PCR) in nasal aspirate but not in blood, urine, and renal tissue. The patient underwent dialysis for 10 days but the response to corticosteroid therapy was quickly observed within 48 h. The mechanism of TIN associated with virus infection is unknown. However, it may be immune-mediated to be able to link severe renal dysfunction and ADV and/or RSV invasion of the respiratory tract.