Chromolaena odorata (Syn: Eupatorium odoratum) is a perennial plant belonging to the Asteraceae family. Extracts of C. odorata have shown strong anti-oxidant and moderate anti-adipogenenesis activities. Detailed phytochemical investigation of C. odorata led to the isolation of 21 secondary metabolites, which include a new flavanone (3), and a chalcone, 3,2-dihydroxy-4,4,5,6-tetramethoxychalcone (2), reported for the first time from a natural source, besides three known compounds 1, 4 and 5, all of which are reported for the first time from C. odorata. Some of these compounds exhibited potent anti-oxidant and anti-adipogenesis activities and these may be partly responsible for the activity of the extract.