There was a deficiency in animal model which showed the results of repairment of the RWM rupture. For this reason we planned to make an investigation in guinea pigs. We created a standard core perforation in the round window membrane of 15 healthy albino guinea pigs. Experimentally produced perforation of the RWM were repaired with gelfoam in right ears and left to spontaneous healing in left ears. The results of the RWM perforation healing process were followed in experimental and control groups. Our comperative histopathologic results which were encountered in light microscope are presented.