We report a case of acute spinal subdural hematoma which developed then reg
ressed spontaneously. MR imaging contributed essential information for diag
nosis and follow-up after conservative treatment. We made a short review of
the literature and discuss the causes, pathogenesis, clinical presentation
and usual treatment of acute spinal subdural hematoma. The differential di
agnosis with the more frequent and extradural hematoma requiring immediate
surgical evacuation is fundamental.