A 30 year-old man with CFTD was reported. He had normal motor milestone during infancy but had been poor at sports. At 28, he experienced exertional and nocturnal dyspnea and had been diagnosed as having dilated cardiomyopathy. At 29, a cardiac pace-maker was implanted because of the complete atrio-ventricular block. Around that time, he began to notice limb muscle weakness. Examination at 30 showed mild diffuse muscle atrophy and weakness at the torso and limbs. No dysmorphic features or joint contractures were noted. His serum CK was normal. A histochemical study of his muscle biopsy showed type 1 fiber predominancy (64.6%) and that the mean diameter of type 1 fibers was smaller than that of type 2 by 14.6% (36.9 microm vs. 42.3 microm). Results of immunostaining of dystrophin, emerin, laminA/C, alpha, beta, gamma, delta-sarcoglycan or dysferlin were normal. He was diagnosed as having CFTD because there were no histochemical abnormalities which characterize other congenital myopathies except for the type 1 predominancy and atrophy.