The histopathological findings in the temporal bones of three patients who underwent endolymphatic subarachnoid shunt operation for Meniere's disease are reported. The postoperative follow-up period varied from three to five years. Two patients had a successful operation; the third was unsuccessful. The continuity between the mesothelial lining of the endolymphatic sac and the subarachnoid space was demonstrated in one case; no definite conclusions could be made for the other two cases. Although failure of shunt surgery was presumably due to fibrosis in the shunt area in the reported case, the human endolymphatic sac seemed to be more resistant to surgical trauma than the sac of the experimental animals.