Treatment with the ketogenic diet has been used to control refractory epilepsy for many years, although its anticonvulsant mechanism is unknown. By modulating synaptic transmission in the hippocampus, kainate receptors and their RNA editing might play a role in the antiseizure action of the treatment. To investigate the potential effect of the ketogenic diet on GluR(5) mRNA and GluR(6) mRNA expression and Q/R site editing, we used the kainate-induced epilepsy model in the present study. Reverse transcription polymerase chain reaction was performed to determine GluR(5) and GluR(6) mRNA expression, and RNA editing was analyzed with the BbvIota restriction enzyme assay. The results demonstrated that expression of GluR(6) mRNA, but not GluR(5) mRNA, was significantly increased after 8 weeks of dietary treatment. Neither the GluR(5) nor the GluR(6) RNA editing rate at the Q/R site was significantly changed by dietary treatment. These data indicate that GluR(6) may be involved in the anticonvulsant mechanism of ketogenic diet treatment.