Emery-Dreifuss muscular dystrophy is characterized by 1) early contractures of the elbows, Achilles tendons, and postcervical muscles, 2) slowly progressive muscle wasting and weakness with a humeroperoneal distribution in the early stages, and 3) cardiomyopathy with conduction defects and risk of sudden death. The inheritance is usually X-linked recessive but can be autosomal dominant and recessive. We report a case of 28-year old woman who presented with dizziness, palpitation, and progressive muscular weakness. Her ECG revealed high degree AV block and muscle biopsy demonstrated diffuse degenerative change consistent with Emery-Dreifuss muscular dystrophy. She was diagnosed as autosomal dominant Emery-Dreifuss muscular dystrophy by characteristic clinical features, and findings of ECG, nerve conduction test, electromyography and muscle biopsy findings. A VVI-type permanent pacemaker was implanted.