Gabapentin is a new antiepileptic drug. Its mechanism of action is not clearly understood, but it seems to differ from that of other antiepileptic drugs. The favourable pharmacokinetic properties of gabapentin make it simple to use. Our preliminary clinical observations with gabapentin at the National Center for Epilepsy are presented. 58 adult patients (mean age 28.9 years), mainly with refractory partial seizures, had gabapentin added to their existing medication. The follow-up period was 6.9 months on average. Only one patient experienced a reduction in seizures of more than 50%, while 25 patients experienced a moderate reduction in seizures (10-50%). The clinical effect was most favourable in patients with secondary generalized tonic-clonic seizures. Gabapentin was well tolerated, and no clinically significant interactions were encountered. Recent observations show that the doses of gabapentin used in our study may have been too low.