Objective: Many patients with Idiopathic Generalized Epilepsy (IGE) exhibit cognitive deficits. Interictal Epileptiform Discharges (IEDs) may contribute to cognitive impairment in epilepsy; however, the relationship between IEDs and cognitive impairment is unclear. Methods:In this study, we analysed executive function in three groups: IGE patients with IEDs, IGE patients without IEDs and healthy controls. Executive function was assessed using the Stroop Test, the Verbal Fluency Test, the Digit Span Test and Wisconsin Card-Sorting Test. Results:The IGE patients with IEDs performed worse on executive function tests compared with patients without IEDs. Furthermore, the IGE patients without IEDs performed worse compared with healthy controls. There were significant differences between the three groups in performance on the Stroop Test, the Digit Span Test (forward and backward), Verbal Fluency Test (animals, fruits) and the subscales of WCST (Categories Completed, Correct Response, Total Errors and Preservative Errors). Conclusion:These results suggest that executive function in patients with IGE is impaired and is further impaired by IEDs. Future studies should determine whether well-controlled patients with IGE could benefit from antiepileptic treatment.