OBJECTIVE: Auditory monitoring in cancer patients. MATERIAL AND METHODS: A total of 10 patients in chemotherapy and/or radiotherapy treatment at an oncology center in Hospital de Urgências de Sergipe took part in this study. Each subject was subjected to anamnesis, otoscopy, pure-tone audiometry, and speech audiometry. Each patient underwent 2 examinations; the second examination was performed 1 month after the first one. The criteria proposed by ASHA were used for analysis of the sequence test. RESULTS: Most of the study participants were women who had breast cancer (60%). Post-surgical cancer treatment involved chemotherapy for 80% of patients and radiotherapy for 60%. Among those who were undergoing chemotherapy, 40% reported subsequent hearing difficulties, and 80% had associated tinnitus; 40% reported sensorineural hearing loss, with the frequency of 6 kHz affected most commonly; and 20% reported that their hearing had deteriorated, as evaluated using the ASHA criteria, at the time of the second examination. There was no significant correlation between the type of treatment and audiometric deterioration (p = 0.545). The Mann-Whitney test showed no correlation between reduced hearing and the number of courses of chemotherapy (p = 0.18) or radiotherapy (p = 0.83). CONCLUSION: Patients undergoing cancer treatment may experience subsequent hearing impairment. Monitoring allows for the adoption of measures designed to improve the patients' hearing and therefore their quality of life.