A 59-year old man developed subacute tetraparesis following severe sudden neck pain. MRI showed a subdural cervical hematoma. Prothrombin complex activity was low. An unusual coagulopathy after rodenticides exposure was found. Diphenacoum, an effective antagonist of vitamin K1, was present in the patients plasma. Specific medical management led to a complete recovery. Follow-up MRI seventy days later confirmed the complete disappearance of the hematoma.