Abstract: A total of 5592 cattle, 10974 sheep and 10066 goats in El Tarf; 49 cattle, 923 sheep and 198 goats in Tebessa and 951 cattle, 20350 sheep, 67 goats and 2731 dromedaries in Ouargla were carefully examined, between 2008 and 2009, for the presence of Echinococcus granulosus hydatid cysts during the routine meat inspection in abattoirs. Also, for the first time in Algeria, the study included 111 wild boars. The prevalence of cystic Echinococcosis in El Tarf was 24.86, 13.83 and 3.71% in cattle, sheep and goats, respectively. In Tebessa, it was 89.80% in cattle, 78.01% in sheep and 67.17% in goats and in Ouargla it was 17.77, 10.83, 8.35 and 7.46% in sheep, cattle, dromedaries and goats, respectively. Concerning Wild boars, the prevalence of cystic Echinococcosis was 6.81 (3/44) and 5.97% (4/67) in El Tarf and Annaba regions, respectively, which giving an overall prevalence of 6.3% (7/111). Livers and lungs were the only infected organs in domestic ruminants. Generally, the most affected organ was the lung. The total annual economic losses from organ condemnation due to hydatidosis was estimated at 28,286; 25,939; 3,309 and USD 3,747 in cattle, sheep, goats and dromedaries, respectively. This epidemiological study confirms the importance of cystic Echinococcosis in slaughtered domestic ruminants in Algeria. Thus, there is a need to introduce appropriate control measures to minimize the rate of infection and reduce the ensuing economic losses and public health consequences of cystic echinococcosis.