The potentiation of cisplatin ototoxicity by noise was explored in the chinchilla. The effects of exposure to cisplatin alone, noise alone or concurrent exposure to both agents were compared in terms of the threshold shift of the auditory evoked potential and the amount of hair cell loss. The combination of cisplatin plus noise produced significantly more hair cell loss and hearing loss at the high frequencies than did either the noise or cisplatin alone when the noise level was 85 dB SPL or higher; no interaction was seen when the noise level was 70 dB SPL. The amount of the interaction, when present, was constant regardless of the noise level. These results indicate that moderate to high levels of noise can exacerbate cisplatin ototoxicity.