In summary, hydatidosis is a common infection that infrequently involves the skeleton. When this happens the prognosis is uncertain because of the possible extension of the disease and serious complications, (e.g., pathological fractures, visceral involvement, neurologic damage from vertebral involvement). For this reason, simple curettage is not sufficient for cure and no medical treatment can surely eradicate the disease. Hydatidosis, in our opinion, should be staged and surgically treated like a malignant tumor (e.g., with wide surgical margins). Medical treatment is useful in association with surgery and remains the only therapy for inoperable lesions. A case of echinococcosis of the hip joint in a 37-year-old man has been reported. In this case the clinicoradiographical features suggested pigmented villonodular synovitis. Proof was obtained on the basis of a frozen section on biopsy. The clinical and laboratory characteristics of hydatidosis were discussed, with emphasis on the medical and surgical treatment of the disorder.