Diffuse astrocytoma with bilateral thalamic involvement is extremely rare. We present a case of 10 years old female who presented with decreased mentation, dysarthria, decreased performance at school and later on with seizures. MRI scans were performed twice and were reported as Leigh`s disease and hemimegalencephaly respectively. Patient presented again with complaint of unconsciousness, vomiting and chest congestion. No further imaging was performed. Biopsy showed grade III Astrocytoma with bilateral thalamic involvement. Patient was admitted to intensive care unit but could not survive and expired.