Four new sesquiterpene lactones, cichoriolide A and cichoriosides A, B and C, have been isolated from Cichorium endivia L. and C. intybus L., together with nine known sesquiterpene lactones. The structures of the new compounds were established on the basis of chemical and spectral data. Further, the cytotoxic activities of related glycosides and the aglycones were compared in the L-5178Y cultured cell system.