Transient left bundle branch block (LBBB) associated with physical exertion has been described in patients with and without coronary artery disease. A 64-year-old woman with no history of coronary artery disease underwent Nissen fundoplication under general anesthesia. Preoperatively, an exercise-tolerance test revealed LBBB, without ischemic symptoms. Intraoperatively, the electrocardiogram revealed normal sinus rhythm. Postoperatively, LBBB appeared in the absence of clinical symptoms or physiologic stress. The patient reported several similar episodes previously. Cardiac enzymes were negative. Subsequent electrocardiograms revealed persistence of LBBB. Anesthesiologists should be aware of the possibility of perioperative transient LBBB in the absence of cardiac ischemia.