The purpose of this study was to investigate the effect of epigallocatechin gallate (EGCG) on the pharmacokinetics of nimodipine in rats. Pharmacokinetic parameters of nimodipine were determined in rats after oral and iv administration of nimodipine with or without EGCG and also the effect of EGCG on the cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp) activity were evaluated. EGCG inhibited CYP3A4 and P-gp activity. EGCG significantly increased the area under the plasma concentration-time curve (AUC) and peak plasma concentration ($C_{max}$) of nimodipine. The absolute bioavailability (AB%) and relative bioavailability (RB%) of nimodipine by EGCG were increased by 16% and by 48%, respectively, compared to the control. In contrast, EGCG did not affect the intravenous pharmacokinetics of nimodipine. Based on these results, the increased bioavailability of nimodipine might be due to inhibition of CYP3A4 in the small intestine and/or in the liver and inhibition of P-gp in the small intestine by EGCG.