Although standard anticonvulsants are effective in achieving complete seizure control in the majority of patients, an appreciable proportion (about 20 to 25%) is at least in part resistant to conventional pharmacotherapy. Efficacy of carbamazepine, phenytoin, phenobarbital and valproate is very similar. Should one drug fail because of inadequate efficacy or unacceptable adverse effects, an alternative monotherapy should be used. Surgical treatment is a feasible therapeutic option for only some of these patients. The development of newer, more effective drugs such as vigabatrin, lamotrigine, gabapentin and oxcarbazepine would be highly desirable. The search for new antiepileptic agents is justified to reduce the proportion of drug-resistant patients. Choice of conventional or new drugs should include not only expected efficacy and risk of adverse effects, but pharmacokinetic properties and expense. Consequently, no general rule is appropriate, and each decision and recommendation for treatment should be individualized.