Spinal subdural hematomas (SDH), even rarer than epidural hematomas, are serious and responsible for permanent neurological deficit without adequate treatment. In this article, we report on a case of cauda equina syndrome after a lumbar puncture in a young patient. Case presentation: A 19-year-old male patient who underwent two lumbar punctures 4 days apart, as part of a work-up for fever and dizziness, presented with genital-sphincter disorders. Clinical examination revealed cauda equina syndrome. MRI revealed an S1- S2 subdural hematoma. An S1-S2 laminectomy with the evacuation of the hematoma was recommended. The evolution was marked by a complete recovery of genitosphincter disorders and sensitivity. Conclusion: Spinal subdural hematoma can be responsible for neurological deficits, sometimes permanent but rarely highly compressive. Management is medico-surgical.