Levetiracetam (LEV) is a novel antiepileptic drug that is eliminated primarily through the kidneys, and has little influence on hepatic metabolism such as cytochrome P450 and glucuronidation. These unique characteristics are an advantage of LEV; however, it is only approved for oral administration in Japan. Therefore, we prepared a suppository containing 500 mg of LEV and evaluated serial changes in plasma concentration of LEV after insertion of the suppository. After confirmation of uniformity of our suppositories (499.10 ± 18.71 mg), this agent was administrated to 6 patients with brain tumors, and blood concentration was measured serially: 1, 2, 4, 8 and 12 hours after administration. In comparison with the reported results after oral administration of LEV, the maximum concentration (Cmax) was low, but prolonged time to maximum plasma concentration (Tmax) resulted in a comparable area under the plasma concentration time curve (AUC). These results suggest that the suppository formulations of LEV produced stable and adequate plasma concentration that could provide a different administration route of LEV.