Subdural empyema represents a loculated suppuration between the dura and the arachnoid. It has been described either intracranially or in the spinal canal, the latter localization being quite rare. It is a rare but serious illness with a declining mortality rate but rather frequent neurological sequelae. Morbidity and mortality in intracranial and spinal subdural empyema directly relate to the delay in diagnosis and therapy. The epidemiology, etiology, pathophysiology and symptoms of spinal subdural empyema and cranial subdural empyema are somewhat different, but brain and spinal subdural empyema are not always two different entities. An adequate treatment strategy should be selected on a case-by-case basis, especially for patients with a massive CNS involvement, where management represents a challenge.