Ginkgo biloba extract (EGb 76 1) has been used therapeutically for centuries. It has attracted great attention as agents for improving circulation, particularly cerebral circulation, which may lead to improved mental function. Many researches hypothesized on the role of the extract in the treatment of diseases involving free radicals and oxidative damage. In the present study, anticonvulsant and antioxidant effects of EGb 761 were investigated in pentylenetetrazol (PTZ)-kindled mice. Valproic acid (VA), a major antiepileptic drug, was also tested for comparison. EGb 761-treated mice displayed a significant attenuated response to PTZ on the test day (day 26) compared with saline-treated and VA-treated animals. Valproic acid significantly increased seizure latency. Pretreatments with EGb 761 significantly protected against PTZ-induced convulsive behaviors (seizure latency, seizure score).