The patient was a 46-year-old woman having a history of multiple sclerosis (MS) for 14 years. She had been treated with interferon β-1b since 2001, but discontinued because of psychiatric problems in 2006. Thereafter relapses were observed 1-2 times a year, and EDSS became 2.5 to 6.5. In April 2012, relapse of MS was noticed and the patient received introduction of fingolimod (FTY) after methylprednisolone (mPSL) pulse therapy. Twenty days later, dysarthria and lower limb weakness were appeared. Brain MRI showed more than 20 several millimeter Gd enhanced lesions in periventricular white matter, juxta-cortical white matter, and cerebellum. Careful determination and observation are required upon the FTY administration into the MS with high frequency of relapse.