The development of small ultrasonographic equipment has permitted to incorporate this technique to the methods of early detection of Human Hydatidosis. 689 ecographies were carried out in this experience, and 5.51% of compatible images in the whole population, and 12.24% in groups of risk (those living together with the operated ones) were found. It was observed a significant decrease in the infection percentages in man in the whole population of areas under Control Program, using the ecographic screening. In conclusion, ecography might be incorporated to the epidemiologic surveillance system of human Hydatidosis.