In the current study, the hydatid cyst-induced tissue lesions in liver and lung of camels and sheep infected with Egyptian strain of E. granulosus was evaluated and the fine structures of the protoscolices by scanning electron microscope (SEM) was described. The results indicated that both fertile and sterile hydatid cysts could lead to various degree of tissue lesions visualized mainly as necrosis, inflammatory cell infiltration and tissue degeneration other histopathological changes occurred in lung and liver of infected animals due to infection with hydatid cyst. Tissue lesion associated with hydatidosis was described. SEM showed envaginated, invaginated protoscolex and the broad capsule of hydatid cyst. There were two types of hooks, large (upper row) and small (lower row) in hydatid cyst protoscolices; with microtriches on different regions.