This case report describes an 80-year-old woman who presented with altered mental status and urinary incontinence. She underwent a lumbar puncture that accidentally resulted in massive cerebrospinal fluid (CSF) overdrainage of 250 mL. Shortly after, she developed multiple simultaneous intracerebral hemorrhages in both supra- and infratentorial regions on CT scan. She became comatose and died within a week. This is the first reported case of massive CSF drainage causing multiple simultaneous intracerebral hemorrhages. The overdrainage likely caused a reduction in CSF volume and intracranial pressure, increasing vessel wall stress and risk of hemorrhage.