In conjunction with a competent medical history, the early diagnosis of acoustic neurinomas is based on the following clinical investigations: pure tone and speech audiometry, caloric testing for nystagmus, and Stenvers radiological examination of the petrous bone. In abnormal studies, audiometry consistently indicates a unilateral hearing loss which is often accompanied by a severe speech discrimination impairment. The caloric response of the affected side is significantly reduced in 90% of the cases. In the same per cent of cases, the Stenvers projection shows significant pathological findings. These include enlargement of the internal auditory meatus, absence of the crista transversa and atrophy of the roof of the internal auditory meatus. As a result of these studies, the possibility of an acoustic neurinoma can be excluded in 50% of cases. Only when these tests yield enough positive findings should more sophisticated studies, such as computerized tomography and meatocysternography, be considered.