Twenty-four patients with head and neck neoplasms were prospectively evaluated for cisplatin (DDP)-induced ototoxicity. Patients were selected from a larger population based on the uniformity of their chemotherapy regimen, renal status, lack of prior or concurrent exposure to ototoxic agents, and availability for repetitive audiometric testing in the same setting. Scanning electron microscopy of the inner ear was performed on four temporal bones. Hearing impairment was found to be dose-related, irreversible within the confines of the study period, and primarily in the higher frequencies. Vestibular toxicity was rare and well-documented by our testing methods in only one patient. Based on the results of this study, and a review of animal and human data on DDP ototoxicity, the authors concluded that ototoxic screening should be reserved for patients defined as “at risk” and those patients receiving more than 400 mg of DDP under the conditions stated in this report. Cancer 56: 1934-1939, 1985.