Excretory/secretory (E/S) products of Echinococcus granulosus were prepared from presentation stages (PS1, PS2, PS3 and PS4) and one segmented (S5) stage which corresponded to 1-, 5-, 12-, 26- and 43-day old in vitro cultured parasites, respectively. Cultures were initiated from protoscolices collected from hydatid cysts of indigenous Jordanian ewes. The E/S products were characterized using SDS-PAGE with silver, Comassie-blue and PAS staining as well as immunobltting with sera from hydatid patients and immunized mice. Younger cultured stages yielded small quantities of E/S materials, compared to the banding (PS4) and segmented (S5) stages. The E/S products from various stages of cultured parasites were heterogeneous and contained 15-28 protein bands and 3-6-PAS+ bands. A total of 13 protein bands were shared among the E/S products of various cultured stages. 11 of which were also shared with crude sheep hydatid fluid (CSHF), tegumental and somatic antigens. The E/S products of PS1-S5 stages and CSHF shared 3 PAS+ bands. All the immunoreactive components of E/S products except for a band of <14.4 KDa, were detected by sera of unicellular hydatid Jordanian patients and were also reactive to sera of patients infected with E. multilocularis.