There has been a large increase in the cost of medical care of patients with epilepsy and this is particularly evident in the cost of drug treatment. This increase is due to the availability of a number of new anticonvulsants such as vigabatrin, lamotrigine, gabapentin and, more recently, topiramate. All these new drugs have significantly higher acquisition costs than the more established anticonvulsants. The increase in the cost of epilepsy care caused by the use of these new drugs has been estimated to be in the region of $US500 million a year in the US.However, estimates of the cost of any treatment may be misleading if formal economic evaluation is not applied. It is important to assess all potential costs, not just acquisition costs, so that cost-effective drug treatment can be rationally planned. For example, it has been shown that anticonvulsants may consume up to 61% of the total cost of medical care for patients with epilepsy, and that if the newer drugs are used this is likely to be significantly higher, even allowing for the increasing costs of other aspects of epilepsy care, such as neuroimaging and epilepsy surgery. However, it is possible that these increases in costs may be offset by savings in other aspects of the costs that patients incur, such as unemployment.Nevertheless, to date, few studies have examined these areas, and claims for the cost-benefit advantages of the new drugs have not been substantiated. Healthcare systems around the world are already assessing policies to curb the rising costs of medical care and this may prevent future new anticonvulsants from being freely available. New drugs with lower risk-benefit ratios are still required by patients with epilepsy and it is hoped that inevitable changes in healthcare funding will not lead to a reduction in new drug development programmes.