Antibodies against monomeric C‐reactive protein, which is a target antigen expressed both in kidney tubules and uveal cells, have been recently detected in patients with active tubulointerstitial nephritis and uveitis syndrome. We report the case of an 65‐year‐old woman with acute renal failure caused by biopsy‐proven tubulointerstitial nephritis and the onset of uveitis 21 months later. The expression of monomeric C‐reactive protein in kidney oligobiopsy was confirmed by immunohistochemical staining using mouse monoclonal antibody against human monomeric C‐reactive protein. The levels of antibodies against monomeric C‐reactive protein were 117% of the reference during the flare and 22% during the remission of the disease. The difference in the levels of antibodies against monomeric C‐reactive protein during flare and remission, and above all positive biopsy staining, supports their pathogenic role in this disease.