Eleven of 12 patients with primary hypoparathyroidism had CT evidence of bilateral intracerebral calcifications, mostly within the basal ganglia, but also in other sites. None of the 12 patients with secondary hypoparathyroidism had intracerebral calcifications. Among 20 patients with calcifications discovered incidentally, idiopathic hypoparathyroidism was diagnosed in 2 patients. Four patients had calcifications associated with antiepileptic treatment, parkinsonism, or Kearns-Sayre syndrome. The cause of the calcifications was unknown in 14 patients. No specific neurologic sign was related to the localization of the intracerebral calcifications. Incidentally discovered basal ganglia calcifications should lead to endocrinologic evaluation of parathyroid function. CT examination of the skull may be used to ascertain the diagnosis of idiopathic hypoparathyroidism.