The piriform and perirhinal cortices are parahippocampal structures with strong connections to limbic structures, including the amygdala and hippocampus, as well as other parahippocampal structures such as the entorhinal cortex. In this paper, we present results, based on anatomical, physiological, and kindling studies, that suggest that the perirhinal and piriform cortices might be very important in the secondary generalization of limbic seizures, particularly those with convulsive expression. These kindling data further suggest that the progressive lowering of afterdischarge thresholds in the parahippocampal structures, due to insult and/or genetic predisposition, might provide the neural basis for the clinical presentation of temporal lobe epilepsy.