The authors report a case of acute nephritis which appears during a treatment with phenindione. The nephropathy described after this medication are now well known. Their manifestations are either a proteinuria associated or not with a nephrotic syndrome or an interstitial nephritis whose pronostic is reserved. In this observation the mechanism is different : the lesion is glomerular and complicates an allergic vasculitis which was secondary to the phenindione's therapy. The pronostic was good.