Calycopteris floribundaLam., commonly known as ‘goichia lata or goache lata’, is a large climbing woody shrub from Bangladesh, and well distributed in a number of other south-east Asian countries. Traditionally,C. floribundahas been used in colic, as an antihelminthic, astringent and carminative, and for the treatment of diarrhoea, dysentery, jaundice and malaria in many countries including Bangladesh. Pachypodol (5,4′-dihydroxy-3,7,3′-trimethoxyflavone) has been isolated from the leaves ofC. floribundaby repeated column chromatography on silica gel, and the structure confirmed by spectroscopic means. While the general toxicity of pachypodol was determined by the brine shrimp lethality assay, the cytotoxic potential of this flavonoid has been evaluated by the Promega's CellTiter 96 Non-Radioactive Cell Proliferation Assay using the CaCo-2 colon cancer cell line (IC50 = 185.6 μM). A summary of the biological activities of pachypodol reported to date is also presented. Copyright © 2008 John Wiley & Sons, Ltd.