Background: In Morocco, Hydatidosis is a common public health problem, as its impact on the health of the animal and consequently its impact on human health. The aim of our study is to clarify the epidemiological data and to estimate the serological test contribution for hydatidosis diagnosis. Methods: A retrospective study was undertaken among 392 patients suspect of hydatid cysts collected between January 2000 to December 2010 at the parasitological laboratory of the Institut National d'Hygiène in Rabat region. The serological diagnosis was used simultaneously with Enzyme Linked Immunosorbent Assay and Indirect haemagglutination test for the detection of specific Echinococcus granulosus antibodies. Results: The overall prevalence of this zoonosis was 37.2 % which women are most affected with 71.2% than 28.8% for men, and sex ratio M / F was 0.5. The prevalence of Echinococcus granulosus varied significantly according to the age and the existence of a surgical history cyst (p <.05). However, gender did not have a significant effect on the prevalence of this pathogen. The kappa coefficient between HAI and ELISA indicated a high level of agreement (0,74). The ultrasound of 181 patients showed that the hydatid cyst involved mainly the liver (68.5%), the kidney (7.7 %) and the lungs (6.1 %). Conclusion: Hydatidosis disease is a non-immunizing with the possibility of recurrence, which requires further monitoring and surgery should be based primarily on ultrasound and serology.