During surgery, cardiac implantable electronic device (CIED) function may be disrupted by electromagnetic interference (EMI) from monopolar electrosurgery and cause adverse sequelae. Monopolar electrosurgery requires a dispersive electrode. While a conventional electrode is affixed to the patient, use of “underbody” electrodes placed on the operating table is increasing. We present a case in which an underbody electrode was used, and EMI occurred even though the surgical site was inferior to the umbilicus. Since little is known about EMI risk with underbody electrodes, practitioners should be wary of their use in CIED patients undergoing surgery until more information is available.