Intramuscular stimulation (IMS) is widely used to treat myofascial pain syndrome. IMS is a safe procedure but several complications have been described. To our knowledge, spinal subarachnoid hematoma has never been reported as a complication of an IMS. The authors have experienced a case of spinal subarachnoid hematoma occurring after an IMS, which was tentatively diagnosed as intracranial subarachnoid hemorrhage because of severe headache. Patient was successfully treated with surgery. Here, we report our case with a review of literature.