Although the cause of sudden unexplained death in epilepsy patients (SUDEP) is unknown, evidence implicates respiratory compromise. Most cases occur while the patient is in bed and unsupervised. We investigated the efficacy of the Medpage bed seizure monitor to detect generalized tonic-clonic seizures. Patients with a history of tonic-clonic seizures were enrolled on a video-EEG unit. The MP5 device was placed between the mattress and bed base between midnight and 8:00 a.m. 64 subjects were enrolled (1528 h). Five of eight tonic-clonic seizures were detected. There were 269 false positive alarms (146 h with false positive alarms). The sensitivity and specificity of the alarm were 62.5% and 90.4%, respectively. The negative predictive value of 99.8% illustrates the potential for this device to provide additional security for patients with tonic-clonic seizures, however individual calibration would likely be necessary to improve the positive predictive value of 3.3%, which requires further validation.