AIM The objective of this study was to assess whether Nd:YAG laser myringotomy has a negative effect on the cochlea. MATERIALS AND METHODS Ten adult guinea pigs with a normal Preyer's reflex were treated by myringotomy with an Nd:YAG laser (power output 8-10W) under surgical microscopic guidance. Preoperative and immediately postoperative hearing tests were performed using auditory brainstem response. The cochlear hair cells were investigated by scanning electron microscope (SEM). RESULTS The mean postoperative hearing threshold of the auditory brainstem response showed an insignificant elevation. SEM findings revealed normal outer and inner hair cells after laser myringotomy. CONCLUSION No negative effect of Nd:YAG laser myringotomy on the cochlea was found. From these results, it can be concluded that the Nd:YAG laser is safe and effective for myringotomy.