Background : Biotin responsive basal ganglia disease (BBGD) is a recessively inherited disorder manifested as subacute encephalopathy .It is  a rare disorder related to thiamine transporterII deficiency caused by mutation in SLC19A3 gene. Administration of high dose of Biotin and thiamine  resulted in significant .Here we report 2 cases of BBGD with different clinical presentation and one with cervical spinal cord  involvement.Case(1): a 13- year- old girl who was previously healthy presented at the age of 11 years with seizure, confusion and abnormal gait. (CSF) analysis was normal. MRI brain showed multiple lesions of high signal intensity involving the basal ganglia , cerebral and cerebellar white matter with alteration in signal intensity of cervical spine.She was diagnosed initially  as Acute Disseminating Encephalomyelitis ( ADEM), received IVIG and methylprednisolone without much improvement.DNA test identifies mutation in SLC19A3 gene. Administration of high dose Biotin and thiamine reverses the symptoms.Case(2) : a 2- year- old girl who presented with a 5 days history of unsteady gait,her brother died at age of 2 years with similar presentation.Her clinical examination showed dystonia. Laboratory investigations showed normal amino acids and urine organic acids profile.MRI brain demonstrated high signal intensity in subcortical white matter, red nuclei and basal ganglia bilaterally.DNA confirmed the diagnosis of BBGD.She responded dramatically to high dose of Biotin and thiamine . Conclusion: BBGD is a rare disorder that should be suspected in patients with subacute encephalopathy and  acute dystonias as early recognition and treatment prevents serious complications and eventually death.