The aim of this study was to analyse carboplatin-induced ototoxicity in a recent study trial. Twenty patients who had received carboplatin for the treatment of soft tissue sarcoma were investigated prospectively for ototoxicity in a multi-centre trial. Hearing function was tested by audiometry. All patients but one were treated with a cumulative dose of 1500 mg/m(2), the remaining with 500 mg/m(2). We evaluated the incidence and dependencies of hearing loss, and compared hearing thresholds to those of an untreated control group (n=60). Hearing thresholds in the carboplatin treated group were only marginally poorer compared with those of the control group. After carboplatin therapy no patient (0%; 95%-KI: 0-17%) had a hearing loss >20 dB. Hearing thresholds were not dependent on age, sex or cranial irradiation. We conclude that ototoxicity after carboplatin was low in our group of patients.