The Bacillus Calmette-Guérin (BCG) vaccine is widely used worldwide. Intracranial manifestation as an adverse event of BCG is extremely rare. A previously healthy 16-month-old boy was referred to our hospital for difficulties in eye contact and progressive gait disturbance lasting 2 months. He was inoculated with BCG at 7 months of age. Brain magnetic resonance imaging (MRI) revealed hydrocephalus with widespread and disseminated enhancement lesions with thickening of the third ventricle floor, and brain tissue pathologically showed noncaseous granulomatous inflammation. Immunosuppressive therapies were initiated because of a provisional diagnosis of neurosarcoidosis. Three months later, a positive polymerase chain reaction (PCR) result for the Mycobacterium tuberculosis complex was obtained. Eventually, M. bovis (BCG Tokyo 172 strain) was identified in the cerebrospinal fluid (CSF) and shunt tube culture. The prolonged use of antituberculosis drugs and multiple shunt replacement surgeries were needed for recovery. There was no evidence of immunodeficiency. Unfortunately, he had severe neurological sequelae such as bilateral blindness and neurodevelopmental delay. Our purpose of this report was to highlight the potential for intracranial manifestations of adverse reactions related to BCG vaccination. We propose that CSF PCR assay of Mycobacterium tuberculosis (MTB) complex should be applied repeatedly in children suspected intractable neurosarcoidosis, with a history of BCG vaccination.Copyright © 2020. Published by Elsevier Ltd.