Whether eye movement desensitization and reprocessing (EMDR) treatment of posttraumatic stress disorder (PTSD) causes reactivation of epilepsy is as yet unclear. A 34-year-old woman was treated in an inpatient multimodal psychotherapeutic setting with EMDR for PTSD resulting from sexual harassment and for a moderate depressive episode. She had been diagnosed with idiopathic generalized absence epilepsy in childhood, but had experienced no seizures under lamotrigine medication since 1999. After the second EMDR session, clinical seizures in the form of absences occurred, and were validated by electroencephalography. The seizures ceased after medication with benzodiazepines and an increase in the lamotrigine level. She underwent four more sessions of EMDR treatment successfully without further seizures. Possible triggers are discussed, especially as to whether EMDR treatment played a role in reactivating epilepsy. Further research and publications on the application of EMDR in epilepsy patients are needed.