The antitumour agent from Ixora javanica flowers shows broad activity against transplantable solid tumours (DLA) in mice by inhibiting the growth of tumour and arresting the growth of already formed tumours; with lesser activity against Ascites tumours. In vitro cytotoxic studies showed 50% cytotoxicity to Dalton's lymphoma (DLA) and Ehrlich Ascites tumour cells at a concentration of 12 micrograms and 65 micrograms, respectively, with no activity against normal lymphocytes but preferential activity for lymphocytes derived from leukemia patients (ALL) (CML), and K 562 suspension cell culture. Tritiated thymidine incorporation studies indicated the mechanism of action of the agent at the site of DNA synthesis. The purified fractions contained Ferulic acid, Pyrocatacheuic acid and caffeic acid.