IN a series of 1,354 cerebellopontine angle tumors treated at the Otologic Medical Group, approximately 10% were lesions other than acoustic neurinomas. Of the non-acoustic tumors, the majority were meningiomas, primary cholesteatomas, and neurinomas of other cranial nerves in the posterior fossa. Twenty-five other lesions were encountered; these rare tumors are the subject of this study. The benign tumors resemble acoustic neurinomas in appearance and in the method of treatment. Malignant tumors are characterized by rapid development of symptoms and are difficult to treat because of invasion of vital structures in the area.