The aim of this study was to investigate the risk of sensorineural hearing loss (SNHL) and the relationship between SNHL and radiation dose to the cochlea and frequency range of hearing loss in patients with head and neck cancer. Pure tone audiometry at 250-12,000 Hz was performed on 29 patients diagnosed with head and neck tumours who were treated with 3-dimensional conformal radiation therapy and followed up for 6 months. Paired t test indicated that the mean air conduction threshold before and after radiotherapy was significantly different (paired t test, p < 0.001). SNHL was observed in 15 patients (51 %) according to CTCAE. SNHL increased to 77 % in patients who had received at least five concurrent cisplatin cycles. There was an increased risk of SNHL for ears receiving a mean dose of 5000 cGy compared to those receiving <5000 cGy. SNHL was more severe at higher frequencies of pure tone audiometry in patients with cisplatin-based chemoradiation. The ototoxicity effect of radiation and cisplatin must be considered in the treatment of head and neck tumours. Increasing the dose of cisplatin, radiation dose of cochlea and follow-up interval time may result in increasing severity and frequency of hearing loss incidences. However, characteristic of radiation-induced SNHL seems to be different from chemoradiation-induced SNHL.