Introduction Fahr's syndrome is a rare but severe brain complication of hypoparathyroidism and its consequences. Case Presentation A 72-year-old female patient was hospitalized in intensive care unit after two generalized seizures along with a severe hypocalcemia, due to hypoparathyroidism following a thyroidectomy for benign nodules and poor compliance with calcium treatment with treatment due to cognitive disorders. Brain CT showed cortical atrophy and extensive bilateral symmetrical calcifications of the cerebellum, thalami and basal ganglia, typical of Fahr's syndrome. Conclusion Nephrologists should be aware Fahr's syndrome in patients with hypoparathyroidism, it is associated with an increased risk of seizures. Thus, the control of calcemia in hypoparathyroidism is important, especially in patients with brain calcifications.