Facioscapulohumeral muscular dystrophy (FSHD) is a common inherited muscular dystrophy presented clinically with slowly progressive weakness and wasting of facial and limb muscles and rare bulbar muscle involvement. We present herein a 70-year-old man who was a known case of FSHD with complaint of 15-day history of progressive difficulty in chewing and dysarthria and was found to have myasthenia gravis. Related literatures have been also reviewed.