Dementia is a risk factor for epilepsy. While seizures have a well-established association with Alzheimer’s disease (AD), their association with dementia with Lewy bodies (DLB) is not established. We utilized the National Alzheimer’s Coordinating Centers’ Uniform Data Set (NACC-UDS V1-3) to analyze occurrence of seizures in DLB and seizure occurrence associations with mortality. We excluded subjects with conventional seizure risk factors. Seizure occurrence was noted in 36 subjects (2.62%) out of 1376 subjects with DLB. Among 500 subjects with pathologically confirmed DLB, seizure occurrence was documented in 19 (3.8%) subjects. Half of the subjects had onset of seizures three years before or after DLB diagnosis. Two-year mortality for subjects with DLB with seizures was high at 52.8% but no increased risk was noted as compared with subjects with DLB without seizures. More prospective and long-term longitudinal studies are needed to clarify relationships between DLB, seizure occurrence, and risk of increased mortality.Copyright © 2020. Published by Elsevier Inc.