We investigated a Japanese pedigree with oculopharyngeal muscular dystrophy (OPMD) which included the probands of two sisters and a brother. Case 1 (Fig. 1): A woman born in 1940 at Fuji City, Shizuoka prefecture (Pacific coast side, which located about 80 miles west from Tokyo) was insidiously suffering from dysphagia and eye lid ptosis since her age of 40. She was admitted to Shizuoka Red Cross Hospital when 48 years old, because of difficulty of going upstairs. Neurological examination revealed severe eye lid ptosis without eye movement disorders, dysphagia, and moderate weakness on neck and proximal muscles of extremities without definite atrophy and fasciculation. In the laboratory data, serum creatine kinase level was slightly elevated to 215 U/l. Electromyographic findings showed myogenic pattern on the extremities but no evidence of the existence of myasthenia gravis and neurogenic involvement. Intranuclear tubular filaments were found in 3% of muscle fibers from her left biceps muscle. Case 2: The elder sister of the case 1 was suffering from eye lid ptosis without eye movement disorder and severe dysphagia since the age of 44. Case 3: The younger brother of the case 1 was suffering from dysphagia and proximal muscle weakness since the age of 40. We found eye lid ptosis, dysphagia and/or proximal muscle weakness in 24 cases (men: 12 cases, women: 12 cases) out of 50 examined members of this pedigree after their ages of 40 (Fig.3; family tree). It was concluded that this pedigree had cases of oculopharyngeal muscular dystrophy with autosomal dominant inheritance which was quite rare in Japanese.