A chronic, bilateral, intra-cranial subdural hematoma was diagnosed in a 28 year old man. A standard diagnostic spinal tap had been performed 6 weeks before. There was no other etiologic factor. Intra-cranial subdural hematoma is a rare complication of either diagnostic, therapeutic, or accidental lumbar puncture. Extensive literature review disclosed the description of 49 other cases, including only 3 cases following a standard diagnostic lumbar puncture. Outcome was fatal in 9 of them. The possibility of an intra-cranial subdural hematoma has to be considered in case of prolonged or unusual headache following a lumbar puncture, even with a headache-free period, knowing the emergency of the surgical therapeutic procedure. The most likely mechanism is subdural venous bleeding induced by the chronic intracranial hypotension due to the persisting lumbar meningeal wound.