Primitive neuroectodermal tumors (PNETs) are easily detected, and the diagnosis made by neuroradiologic imaging. Leptomeningeal seeding is a common complication and carries a poor prognosis. Primary leptomeningeal PNETs are rarer and difficult to diagnose on magnetic resonance imaging (MRI) or cerebrospinal fluid (CSF) studies. We encountered a rare case of primary leptomeningeal primitive neuroectodermal tumor without intracranial mass lesion which was diagnosed by spinal lesion biopsy. This 25-year-old woman presented with worsening headaches and progressive visual impairment.The initial diagnosis was tubercle bacillus (TB) meningitis, and the final diagnosis of primary leptomeningeal PNET was made by spinal biopsy. We present this illustrative case, review previous cases in the literature, and suggest that diagnosis is considered in mildly affected patients with similar symptoms.