Phytochemical study of the leaves and bark of Crescentia alata HBK. (family Bignoniaceae) using chromatographic techniques yielded three compounds isolated from the bark: a phenylpropanoid, 4-hydroxy-3-methoxybenzoic acid (vanillic acid); a triterpenoid, lupeol; and a flavonol glycoside, quercetin-3-rutinoside (rutin), and one compound from the leaves: a sterol, 24-ethyl-5,22-cholestadien-3-b-ol (stigmasterol). The structure elucidation of these compounds were accomplished through the analysis of their UV, IR, MS, 1H-NMR and 13C-NMR, especially the 1D-NMR and 2D-NMR, data, together with comparison with reported values. Screening test of crude extracts and pure compounds from this plant for antioxidant activity using DPPH indicated their activity to be comparable with vitamin E.