Stiff limb syndrome is a recently described variant of stiff man syndrome and is characterized by limb stiffness and spasms. Unlike stiff man syndrome, stiff limb syndrome is rarely associated with anti GAD antibodies, poorly improves after symptomatic treatment, and has a relapsing and remitting course. Both stiff man and stiff limb syndromes are frequently associated with auto-immune diseases. We report a case of a 70-year old man who presented with a stiff limb syndrome associated with symptoms highly suggestive of Hashimoto's encephalopathy. The signs of encephalopathy dramatically resolved after corticosteroid treatment, and remissions was complete after 12 months. The stiff limb syndrome had a remitting course despite symptomatic treatment including diazepam, baclofen and vigabatrin and immunomodulating treatments including corticoid and intravenous immunoglobulins.