A healthy 21-year-old man had laser in situ keratomileusis (LASIK) in the right eye for a refractive error of -7.0 diopters. The electrocardiogram findings and heart rate were recorded before LASIK; during eye lid speculum insertion, vacuum application, corneal flap preparation, and excimer laser keratectomy; and after the procedure. The pre-LASIK heart rate was 90 pulses/min. Severe bradycardia of 40 beats/min developed during vacuum application, and the procedure was terminated. Severe bradycardia caused by an oculocardiac reflex may occur during LASIK, and patients should be closely monitored during the procedure.