Introduction: Methods: We compared the problems or complications associated with electrodiagnostic testing in 77 patients with implanted cardiac devices. Thirty tests were performed after magnet placement, and 47 were performed without magnet application. Results: All electrodiagnostic tests were performed safely in all patients without any serious effect on the implanted cardiac devices with or without magnet placement. A significantly higher number of patient symptoms and procedure changes were reported in the magnet group (P < 0.013). No statistical difference was found in the testing difficulty or ECG changes. Conclusion: The magnet group patients had an approximately 11-fold greater risk of symptoms than those in the control group. Our data do not support a recommendation that magnet placement is necessary for routine electrodiagnostic testing in patients with implanted cardiac devices, as long as our general and specific guidelines are followed. © 2012 Wiley Periodicals, Inc.