BACKGROUND: Hydatid disease is caused by the larval form of Echinococcus granulosus. The reported occurrence of bony hydatidosis is 0.5–3% of all the cases and 50% of them affect the spine. Nevertheless, lumbar vertebral involvement is extremely rare. The most common occurrence is the dorsal level. CASE REPORT: We present the case of a 32-year-old-military dog handler, who presented in 2018 to the urology department with an abdominal retroperitoneal mass. The MRI showed multilocular cystic lesions. The patient underwent surgery, and all of the cysts were removed. The anatomopathological evaluation concluded to hydatic cysts. He was briefly relieved from his symptoms. He was addressed to our department in 2020 suffering from lumbar-radicular pain and functional impotence of both lower limbs. MRI was performed showing multiple big cysts with inhomogeneous contents. CT scan showed destruction of the l5 vertebra. The patient underwent surgery. Initially, we performed through a posterior approach, an L4 to S1 laminectomy, posterior stabilization, and then total L5 corpectomy, anterior l4-s1 fusion through a xipho-pubic laparotomy after 2 months. Antihelminthic therapy was administrated. The patient’s symptoms completely disappeared. No signs of reoccurrence were noted at the 2-year follow-up. CONCLUSION: The primary extrahepatic cystic echinococcosis of bone is an extremely rare disease. Diagnosis can be long and difficult. It can lead to serious complications and should be highly considered in case of a cystic vertebral lesion in an endemic region. Spinal involvement is extremely rare but potentially curable with surgery and anthelmintic drug therapy.