Abstract 1. Similarly to that found in Bufo marinus, the urinary bladder of Rana esculenta, ADH-treated, exhibits a facilitated transport of urea at the luminal membrane. 2. The functional removal of luminal barrier by amphotericin B reveals the presence of a saturation mechanism of urea transport across the baso-lateral membrane, in the absence of ADH. 3. Phloretin, a specific inhibitor of ADH induced urea transport, markedly inhibits urea transepithelial flux even when put in the serosal side. 4. Washing out of urea on the serosal side (without ADH) demonstrates the presence of a counterflow acceleration, specifically elicited by an urea gradient. 5. The findings above demonstrate the existence of a facilitated transport of urea even at the basolateral membrane of the Rana esculenta urinary bladder.