✓ From among 1500 patients who underwent computerized tomography (CT) during an 18-month period, five cases of hydatid disease of the brain were diagnosed. The preoperative diagnosis is of paramount importance as the cyst has to be removed unruptured. The CT features of this condition are practically pathognomonic. The authors discuss the CT findings in these cases and differential diagnosis with other cystic lesions of the brain. The help that this safe and sure method of investigation gives to attain preoperative diagnosis is emphasized.