Although anticonvulsant polytherapy has traditionally been used on a large scale in epilepsy, there is little evidence that it has advantages over monotherapy. Furthermore, it leads to problems of chronic toxicity, drug interactions, failure to evaluate individual drugs, and sometimes exacerbation of seizures. In many cases polytherapy could be avoided by more careful monitoring and supervision of patient's compliance. Studies in new, previously untreated patients suggest that there is considerable potential for monotherapy. In chronic patients on polytherapy, there may be opportunities for careful rationalization to two or even one drug, with subsequent reduction of chronic toxicity and sometimes improvement in seizure control. Reduction of the number of drugs, however, may be impossible or hazardous owing to withdrawal seizures. It is easier to avoid polytherapy than to reduce it.