The use of genetically altered mice has revolutionised biomedical research into the genetics and neurobiological mechanisms contributing to complex human disorders such as epilepsy. Recent studies using mutant mice have expanded our knowledge of the key roles that abnormalities in synaptic function and formation play in epileptogenesis, and further illustrate just how closely some mouse models resemble human epilepsy. Broader utilisation of epileptic mouse mutants should provide new molecular targets for developing novel anti-epileptic drugs, and also improved means for predicting their efficacy in currently refractory forms of epilepsy.