Background: Implantable hypoglossal nerve upper airway stimulation (HNS) is a novel strategy approved by the US Food and Drug Administration for the management of moderate-to-severe obstructive sleep apnea (OSA) in patients with continuous positive airway pressure therapy intolerance or failure. Because of the proximity of a cardiac implantable electronic device (CIED) to this stimulator, interaction between these devices is theoretically possible. Objective: The purpose of this study was to assess interactions between an implantable HNS device and a CIED. Methods: We retrospectively analyzed 14 ad hoc patients with continuous positive airway pressure-intolerant, moderate-to-severe OSA and pre-existing transvenous CIEDs undergoing HNS implantation (Inspire II, Inspire Medical Systems). We assessed these devices for their pre and postimplant OSA outcomes and for possible device–device interaction. All patients were followed up for 1 year. Results: Of the 14 patients, 9 had a pacemaker (8 dual-chamber, 1 single-chamber), 4 had an implantable cardioverter-defibrillator (2 dual-chamber, 1 single-chamber), and 1 had a cardiac resynchronization therapy device. All the HNS devices were implanted on the opposite side of the CIED. All CIEDs were programmed bipolar. HNS were programmed either unipolar or bipolar. During implant, intraoperative testing was performed to confirm that bipolar and unipolar HNS stimulation did not impact CIED sensing. During the follow-up period, no oversensing episodes were noted on the CIEDs. Conclusion: In this early experience, simultaneous use of a novel hypoglossal nerve upper airway stimulation device with transvenous CIEDs seems to be safe, effective, and without any device–device interactions.