Patients under treatment of hemodialysis (HD) frequently exhibit some degree of sensorineural hearing loss. Fifteen subjects and 10 controls were tested by using pure-tone audiometry (PTA) and distortion-product otoacoustic emissions (DPOAEs) before and after a HD treatment. Other parameters (blood pressure, body weight, blood chemistries) were also evaluated before and after HD: The purpose of this study was to determine the acute effect of HD on hearing level by measuring PTA and DPOAE before and after one HD session. The results from PTA and DPOAE testings showed that hearing was unaffected by HD. However, all 15 subjects revealed significantly poorer hearing, especially in the higher frequencies, compared to that of the controls (p < 0.0001). It was concluded then that HD is a safe treatment, and that the sensorineural hearing loss in these patients may be attributed to the preexisting renal disease.