Normal and neoplastic human intracranial tissues were examined by immunohistochemistry for c-erbB-2/HER-2 protein expression. Positive staining was observed in 1/41 gliomas, 1/2 medulloblastomas, 1/1 germinoma, 11/16 meningiomas, 1/3 anaplastic meningiomas and 11/19 metastatic brain carcinomas. No positive staining was observed in normal intracranial tissues. Thus, the expression of the c-erbB-2/HER-2 protein is limited to intracranial tumour tissues, principally meningiomas and metastatic carcinomas to the brain.