Although hydatid disease is the most common human disease caused by helminths, cerebral and spinal involvement in hydatid disease is rare. Recurrence is common when cysts rupture during surgical removal. The authors present the results of combined treatment with surgery and mebendazole in four cerebral and fi ire spinal cases of hydatid disease. The patients' ages ranged between 4 and 55 years with a mean of 26 years. In three of the four cranial patients who received mebendazole treatment, the cysts ruptured during surgical removal. Four of the five spinal cases had recurrent disease at the time of admission. Mebendazole was started immediately after surgery and continued over 12 months. All cases but one ape stable clinically or radiologically at a mean 27 months follow-up period.