Basal ganglia calcification was found as an incidental finding in 42 out of 7000 patients who underwent computed tomography. The calcification showed on plain skull radiography when the maximum density on computed tomography exceeded 100 Hounsfield units. The 26 patients with basal ganglia calcification detected on computed tomography who were available for follow-up, were investigated with matched controls. No clinical features of basal ganglia calcification were noted. Twenty-four patients had no significant metabolic abnormality and two patients had parathyroid disorder identified.