A new physiologic morcellating resectoscope allows operative hysteroscopy to be performed with a physiologic distention medium, thus reducing the risk of dilutional hyponatremia and cerebral edema secondary to excessive absorption of nonphysiologic fluid. To study this new technology, we gathered in vitro data with the SL resectoscope with dual-function electrode (FemRx, Sunnyvale, CA). Coupled to a standard monopolar electrosurgery unit and operating in normal saline or Ringer's lactate solution, extirpated uteri showed equivalent depth of tissue necrosis with this new physiologic morcellating resectoscope as with a conventional monopolar resectoscope used in an electrically nonconductive fluid.