Calcium ions have important roles on the regulation of cellular functions. It is thought that calcium flux into the cell is the first step of epileptic neuronal events. In the present study, the effect of nifedipine on experimental model epilepsy induced by intracortical (i.c.) penicillin administration was investigated. The left cerebral cortex was exposed by craniotomy in urethane-anaesthetized rats. The epileptic focus was produced by injection of penicillin G potassium (500 units) into the somatomotor cortex. Microinjection of nifedipine into the same area caused 25-55 % decrease in the average number and amplitude of spikes for 3-6 minutes (p<0.01). The 100 µM dose of nifedipine was more effective than 50 µM (p<0.05). The results of this study suggest that nifedipine may be an anticonvulsant agent inducing its effect by preventing calcium flux into the cell.