Immunoglobulin G4-related disease (IgG4-RD) is an emerging fibro-inflammatory condition known to involve potentially every organ system in the body, especially the kidneys, and is characterized by interstitial nephritis, obstructive nephropathy, and in rare cases, glomerular nephropathy. In this article, we report two cases of IgG4-RD with renal manifestations, hospitalized in the Department of Internal Medicine of the Principal Military Hospital of Instruction of Tunis. In conclusion, the clinical course of IgG4-related kidney disease varies widely and it can sometimes be difficult to diagnosis. A multidisciplinary approach can be useful. Early diagnosis and appropriate therapy are very important.