The cerebellum of a vertebrate not only receives signals from the motor areas of the cerebral cortex but also receives different impulses indirectly from almost all sensory receptors. WithEptesicus fuscus, we studied the response properties of cerebellar neurones to acoustic stimuli (40 ms duration, 0.5 ms rise‐decay time). Single neurones responding to auditory stimuli could be isolated from rather large areas of the bat's cerebellar vermis and hemispheres. They were usually spontaneously inactive and discharged either tonically or phasically. These units had latencies between 4 and 13 ms and best frequencies between 22 and 77 kHz. TheQ10‐dB values of their triangular tuning curves were between 1.4 and 16.6 with the majority below 10. Minimum thresholds were between 12 and 65 dB SPL. When acoustic stimuli were delivered through the earphones, tuning curves measured from each ear alone were nearly identical in shape and best frequency. At present, we do not know whether the units we studied were exclusively auditory or multimodal neurones [Work supported by DFG of West Germany and NSF of USA.]