The purpose of this study is to investigate the diagnostic value of using the damped pendular rotation test (DPRT) (1) with an ocular fixation (ocular fixation test, i.e. OFT), and (2) in the dark with the eyes open, jointly with auditory brain stem response (ABR) audiometry. Impairment of ocular fixation was found in patients with either brain stem lesions, cerebellar lesions, or cerebellopontine angle tumors. A collective evaluation of the findings of OFT with those of ABR audiometry has suggested the possibility of differentiating upper brain stem lesions from lower brain stem lesions, tumors of the IVth ventricle, and cerebellar tumors. However, differentiating IVth ventricle lesions from tumors involving the cerebellar vermis extending into the IVth ventricle by this battery of tests was somewhat limited.