Vitex rotundifolia L. fil. (Verbenaceae) is widely distributed in Asia, and its fruit (Viticis trifoliae Fructus) is used in folk medicine for headaches. Previous studies have reported the presence of diterpenes, flavones, lignan, phenylpropanoides, 3,4-dihydroxybenzoic acid and iridoids in this fruit. In this study, the MeOH extract of the fruit showed stronger antioxidative activity than tert-butylhydroxyanisol (BHA), a synthetic antioxidant, using the ferric thiocyanate method. Therefore, the components were reexamined to determine the compounds responsible for the antioxidative effect. The powdered fruit was extracted with MeOH at room temperature, defatted with hexane, and the residue (with stronger antioxidative effect than the hexane-soluble fraction) was subjected to Diaion HP20, Sephadex LH20, silica gel column chromatography, and HPLC on octadecyl silica (ODS), resulting in the isolation of two new iridoids (viteoids I and II) along with six known iridoids (eucommiol, iridolactone, pedicularis-lactone, agnuside, VR-I and 1-oxoeucommiol). The chemical structures of viteoids I and II were determined based on spectroscopic data including positive FAB-MS, HR positive FAB-MS, IR, 1H-NMR, 13C-NMR, 1H-1H shift correlated 2D-NMR (COSY), 1H-13C heteronuclear shift correlated 2D-NMR (HETCOR), 1H-detected heteronuclear multiple-bond multiple-quantum coherence (HMBC), difference nuclear Overhauser effect (NOE) experiment and coupling constant values. Compound 5 showed stronger antioxidative activity than BHA using the ferric thiocyanate method.