Idiopathic generalised epilepsy (IGE) is subdivided into syndromes based on clinical and EEG features.Purpose: The aim of this study was to characterise all cases of IGE with supportive EEG abnormalities in terms of gender differences, seizure types reported, IGE syndromes, family history of epilepsy and EEG findings. We also calculated the limited duration prevalence of IGE in our cohort.Methods: Data on abnormal EEGs were collected retrospectively from two EEG databases at two tertiary referral centres for neurology. Clinical information was obtained from EEG request forms, standardised EEG questionnaires and medical notes of patients.Results: two hundred twenty-three patients met our inclusion criteria, 89 (39.9%) mate and 134 (60.1%) females. Tonic clonic seizures were the most common seizure type reported, 162 (72.65%) having a generalised tonic clonic seizure (GTCS) at some time. IGE with GTCS only (EGTCSA) was the most common syndrome in our cohort being present in 94 patients (34 mate, 60 female), with 42 (15 mate, 27 female) patients diagnosed with Juvenile myoclonic epilepsy (JME), 23 (9 mate, 14 female) with Juvenile absence epilepsy (JAE) and 20 (9 mate, 11 female) with childhood absence epilepsy (CAE).EEG studies in all patients showed generalised epileptiform activity.Conclusions: More women than men were diagnosed with generalised epilepsy. Tonic clonic seizures were the most common seizure type reported. EGTCSA was the most frequent syndrome seen. Gender differences were evident for JAE and JME as previously reported and for EGTCSA, which was not reported to date, and reached statistical significance for EGTCA and JME. (c) 2006 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.