Emergency clinicians must have a high index of suspicion and a judicious approach to evaluating the chief complaint (ie, headache) of patients with suspected subarachnoid hemorrhage, as accurate initial diagnosis and management are critical to optimizing outcomes. Aneurysmal subarachnoid hemorrhage accounts for a small percentage of strokes, but contributes significantly to the morbidity rate in stroke. The diagnosis is challenging and has devastating consequences if missed. This review evaluates the literature and current evidence, including controversies and recent guidelines, to support a best-practice approach to the diagnosis and treatment of patients with spontaneous subarachnoid hemorrhage.