The severe epilepsies of childhood are described briefly and information available on the efficacy of newly developed antiepileptic drugs (AEDs) in their control is reviewed. Therapeutic advances are awaited for early infantile epileptic encephalopathy, early myoclonic encephalopathy, progressive myoclonus epilepsies and Kojewnikow syndrome. West syndrome may respond to vigabatrin, and less predictably to lamotrigine. Lamotrigine can be helpful for severe myoclonic epilepsy and myoclonic absences. Astatic seizures may be dramatically controlled by lamotrigine, whereas vigabatrin may worsen myoclonic attacks. In the Lennox-Gastaut syndrome, the efficacy of felbamate has been demonstrated by a controlled trial; vigabatrin and lamotrigine can also be helpful. Non-idiopathic partial and secondary generalized epilepsies are responsive to vigabatrin in a useful percentage of cases, and some children improve with felbamate, lamotrigine or stiripentol.A trial which compares the efficacies of the newer AEDs against each other could provide very useful information for the clinician.