Immunohistochemical evaluations with antibodies against S-100 protein, glial fibrillary acidic protein, cytokeratin and prealbumin were applied to 2 intracranial cysts of choroidal epithelial and neuroepithelial origin, and to the normal choroid plexus and ependyma. All specimens showed various immunoreactivities with the 4 antigens: especially, prealbumin-positive cells were detected in normal choroid plexus, part of normal ependyma, and part of choroidal epithelial cyst. The epithelium of neuroepithelial cysts presumably has multipotentials in cellular differentiation.