A patient with cytoplasmic body myopathy presented muscle hypotonia from birth and developed progressive muscular atrophy and weakness, scoliosis, contracture of joints and cardiorespiratory failure. At the age of 17, he died of heart failure. Post mortem examination revealed severe hypertrophy of cardiac walls and generalized muscular atrophy. Microscopic examination showed many cytoplasmic bodies in skeletal muscle fibers and myofiber disarray in myocardium. No cases of cytoplasmic body myopathy with hypertrophic cardiomyopathy have been reported previously. It is suggested that the Z-line component is related to the formation of the cytoplasmic body in skeletal muscle and disarray in the cardiac muscle.