A new animal model of ototoxicity is presented using intravenous carboplatin in adult chinchillas. A range of physiological and morphological effects was produced using doses calculated from the recommended therapeutic range (200–400 mg/m2). Auditory thresholds to tone pips stimuli were monitored using brain stem evoked responses (ABR). Cochlear histopathology was studied by light microscopy (LM) and ultrstructural hair cell abnormalities investigated with scanning electronmicroscopy (SEM). Carboplatin in this animal model predominantly affected the inner hair cells. This may provide an important model for the study of selective loss of the main afferent input in the auditory system.