Epilepsy is a common and serious neurological disorder. Despite recent advances in drug therapy, treatment for epilepsy is still largely empirical and rational prescribing based on the mechanism of action in an individual patient is generally not possible. Genetic studies have identified an increasing collection of disease-causing genes providing a fundamental molecular foundation on which to build this understanding, at least for some forms of epilepsy. The impact of these genetic discoveries is likely to be wide reaching—from the discovery and validation of new drug targets to the potential to enable rational prescribing based on genetic makeup and even further through animal experimentation to tease out molecular and cellular mechanisms that lead to hyperexcitable neuronal networks causing epilepsy. Here we discuss how we can use knowledge of genetic mechanisms to improve treatment strategies now and into the future.