BACKGROUND Fahr's disease (FD), or primitive idiopathic calcification of the basal ganglia, is a rare neurodegenerative syndrome characterized by the presence of idiopathic bilateral and symmetrical cerebral calcifications. CASE REPORT We describe the case of 43-year-old woman presenting with psychiatric symptoms, disorganized behavior, and migraine. Magnetic resonance imaging (MRI) examination showed basal ganglia calcifications. In addition, we analyzed the cortical brain volume and noted cortical atrophy. Extensive etiological clinico-biological assessment allowed us to exclude known causes of brain calcifications and to diagnose Fahr disease (FD). Neurological symptoms associated with psychiatric manifestations are not uncommon in FD. CONCLUSIONS Purely psychiatric presentations are possible, as demonstrated by the present case, although there have been very few cases reported. To date, no studies related to the brain atrophy in FD have been reported.