In this study, we examined the antimutagenicity of red pepper seed and red pepper pericarp ethanol extracts using the standard Ames test in the presence and absence of S9 mix. The extracts showed inhibitory effects on both the TA98 and TA100 Salmenella Typhimurium strains against the mutagenic activity of promutagen 2-aminoanthracene, and were also protective against the directly acting mutagens sodium azide and 2-nitrofluorene. The red pepper seed elicited stronger antimutagenicity than the red pepper pericarp. Both the red pepper seed and red pepper pericarp directly quenched nitric oxide to different degrees and the scavenging activities increased with increasing concentrations. Nitric oxide scavenging activity ranged from $22{sim}77%$ in the red pepper seed, and from $36{sim}49%$ in the red pepper pericarp. The TEAC values for red pepper seed extract were $47.89{pm}1.64mg;g^{-1}$ in the ABTS radical scavenging assays, while those of red pepper pericarp extract were $94.18{pm}1.61mg;g^{-1}$. Therefore, we conclude that red pepper seed and red pepper pericarp have antimutagenic activities as well as antioxidant activity.