Spinal subdural hematoma is a rarely reported disease and spontaneous spinal subdural hematomas (SSDH) without underlying pathological changes are even rarer. The patients usually show typical symtoms such as back pain, quadriplegia, paraplegia or sensory change. But rarely, patients may show atypical symptoms such as hemiparesis and misdiagnosed to cerebrovascular accident. We recently experienced a case of SSDH, where the patient initially showed vague symptoms, such as the sudden onset of headache which we initially misdiagnosed as subarachnoid hemorrhage. In this case, the headache of patient improved but the neck pain persisted until hospital day 5. Therefre, we conducted the MRI of cervical spine and finally confirmed SSDH. The patient was managed conservatively and improved without recurrence. In this case report, we discuss the clinical features of SSDH with emphasis on the importance of an early diagnosis.