Ototoxicity is one of the unwanted side-effects of a number of medical drugs. As ototoxicity appears to be most pronounced in the higher frequencies, it can be assessed at an earlier stage by using high-frequency audiometry from 8 to 20 kHz. We have investigated the precision of these measurements. In spite of inaccuracies of headphone positioning, which may influence especially the high-frequency thresholds, standard deviations for frequencies above 8 kHz were obtained that were nearly as small as for audiometry up to 8 kHz. Age-related reference curves for the higher frequencies are presented. The results on 100 ears of patients treated with platinum-derivatives show the importance of high-frequency audiometry for the early detection of ototoxicity.