Idiopathic generalized epilepsy (IGE) comprises several subsyndromes. These are principally: benign neonatal familial convulsions, benign neonatal convulsions, benign myoclonic epilepsy in infancy, childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, epilepsy with generalised tonic-clonic seizures on awakening. In addition, there are less well-recognized syndromes, such as eyelid myoclonia with absences. The pathophysiology of the IGE syndromes is not fully understood; it is evident that typical absences are the result of abnormal oscillations between the thalamus and cerebral cortex. Genetic studies are in progress to elucidate the biochemical defects underlying the conditions. The clinical and electroencephalographic features of the individual subsyndromes are distinct, but some patients may be difficult to classify into a particular subgroup. A correct syndromic diagnosis is important, as treatment strategies differ for patients with the different forms of IGE, and it is necessary for genetic research.