Introduction : We report  cerebellar calcification  and seizures  a rare presentation of hypothyroidism  in a child with auto immune poly endocrine syndrome 3 A.Case report : A six year old girl  with global developmental delay presented with polyuria and weight loss for two weeks and seizures  six months prior .  She had dysarthria, ataxia, proportionate short stature with bone age of three years and six months. Random blood sugar -369 mg/dL and urine   ketones  was positive. TSH was > 100  and Free T4  was low.  Anti TPO antibody was 813.59IU/ml and  anti GAD  antibody was >2000IU/ml . Non-enhanced CT scan of the brain showed bilateral symmetrical calcification and mild atrophy of the cerebellar folia [Fig 1]. She was diagnosed to have Autoimmune Polyendocrine Syndrome Type 3A due to the presence of   hypothyroidism and Type 1 diabetes mellitus.Discussion : Delay in diagnosis and treatment of hypothyroidism especially in the early childhood or post -natal period  may present with neurological signs like developmental delay ,seizures, dysarthria, ataxia ,spasticity  along with cerebellar atrophy and calcification.  Hypothyroidism is known to cause calcification in the basal ganglia, subcortical areas and rarely in the cerebellar folia probably due to metabolic  derangements . Low levels of thyroid hormones may  contribute to epileptogenesis .Conclusion : Hypothyroidism being a treatable condition should  be ruled out in any child presenting with symptoms like developmental delay, seizures, spasticity, cerebellar dysfunction with neuroimaging findings such as intracranial calcification and cerebellar atrophy.