Background: Subdural hematoma is very often associated with head trauma. There are few documented cases of spontaneous acute subdural hematoma without a history of Case presentation: A 50-year-old man was admitted for a mild-intensity headache in helmet-like, which occurred in the night without any cause waking him up from his sleeping. He denied any drug taken, mainly anticoagulant, non-steroidal anti-inflammatory drugs. The neurological exam was absolutely normal. The head CT Scan performed showed a thick left fronto-temporal spontaneous acute subdural hematoma The blood investigations were normal. Brain angio-CT didn’t show any The patient benefited fromconservative treatment under observation and experienced a progressive regression of the headache throughout the hospitalization stay. He was discharged an eleventh day later. Conclusion: Spontaneous acute subdural hematoma is a rare entity. It requires painstaking clinical, biological, and imaging and a strict follow-up for its management.