Some pathological features of tumors arising primarily in the meninges are discussed on the basis of 412 surgically treated meningiomas during the period running from 1964 to 1978. Cases of meningeal sarcomas were not considered. Except for a few cases, pathology and clinical course have been generally in agreement. The incidence of histological types like meningotheliomatous, fibroblastic, angioblastic or atypical meningiomas has been verified in relation to sex, age and intracranial or spinal conventional locations. The problem of recurrencies has been studied either comparing the histological features with the first observation or comparing histopathological types with location and details of surgical procedure. Additional criteria like uni or multifocal origin of the tumors and histological features of the peri-lesional tissues, often harbouring small meningiomatous nests, have been taken into account.