Bone infection is estimated to represent 0.5-2.5% of cases of hydatid disease. Of these cases, the spine is affected in about 50%. 11 cases of histologically confirmed spinal hydatid disease treated surgically in 2 institutions in Spain and Lebanon were followed up clinically and radiologically for an average of 20 y (1-34 y). On presentation, all patients had severe neurological deficits. All patients underwent posterior spinal decompression, curettage, drainage and washout of paravertebral cyst cavities. Over the period of follow-up, patients underwent an average 4.8 spinal surgical procedures. Neurologically, all patients had partial or complete spinal cord lesions. All patients had recurrences and 18% died as a consequence of the disease. Extravertebral dissemination occurred in 82% of the cases, most commonly to the liver.