Research areas of immunodiagnosis and vaccination in Cystic Echinococcosis (CE) are reviewed. Particular attention is given to recent progress into improved specificity in immunodiagnosis in human CE, and sensitivity and specificity in ovine CE, by purification of subunit peptides of Ag B. With regard to diagnosis in definitive hosts, the advantages of coproantigen test ELISA are discussed in comparison with the classic arecoline purgation test. Recent data from studies on vaccination in sheep populations are reported, and the enormous potential of an effective vaccine in a Hydatid control programme is underlined.