The aim of this work was to evaluate hippocampal neurons in the rat brain after single and repetetive seizures induced by pentyleneterazol (PTZ) administration at light- and electron-microscopically. Acute- and chronic-PTZ groups of male Wistar albino rats were given PTZ intraperitoneal injection (i.p.), and the age-matched rats in control group were injected with normal saline. We determined contributions of apoptosis and necrosis to neuronal damage in Nissl-stained- and ultrathin-sections. Necrotic neurons were observed in PTZ-treated groups, especially in the chronic-PTZ group. Histological changes were perikaryal swelling, chromatolysis and decreasing of Nissl in the necrotic neurons. Necrotic and apoptotic neurons of the hippocampus were observed ultrastructurally in the PTZ groups. These findings demonstrated a significant decrease in the number of hippocampal neurons in the chronic-PTZ group. It is clear that in the hippocampal regions repeated PTZ-induced seizures of the rats cause neuronal damage and neuronal loss