Résumé : Several recent publications have suggested that the use of cuprophane in the setting of acute renal failure is associated with a higher mortality (especially from sepsis) and a slower recovery of renal function in the survivors in comparison with more biocompatible membranes. We present here a critical review of these publications and point to several methodological bias that might invalidate their conclusions. However, while waiting further information, we would advocate to abandon the use of cuprophane to dialyze patients with acute renal failure.