Two families of dilated cardiomyopathy are reported. In the first family, two sons were affected. The elder child presented with congestive symptoms at the age of 5 months and was diagnosed to have dilated cardiomyopathy. The etiology of cardiomyopathy was thought to be idiopathic until his younger brother presented with near collapse at the age of 5 days and was diagnosed to have the same dilated cardiomyopathy. In both patients, total carnitine was slightly low and esterified form was not measured. Other metabolic screening, such as amino acid level, ammonia, and lactate level was within normal limit. The parents are unrelated and there is no other person in their family who have dilated cardiomyopathy. Both patients are on carnitine and anticongestive measure, but no significant changes in shortening fraction and left ventricular dimensions have been observed. In the second family, two daughters were affected. The first pregnancy of unrelated couple ended in spontaneous abortion at a gestational age of 8 months. The second pregnancy resulted in a normal girl who is well and currently 9 years old. The third pregnancy produced a normal looking girl, but died of dilated cardiomyopathy as a neonate. The fourth pregnancy (propositus) was screened for fetal heart, which showed poorly contracting dilated both ventricles. The girl was delivered by section at a gestational period of 39 weeks. She also presented with congestive symptoms as a neonate and laboratory test showed that total carnitine was slightly low and esterified form was normal. Other metabolic screening was negative. She was treated with digoxin, diuretics, vasodilators, and carnitine, but has not shown any changes in symptoms or echocardiographic findings. As far as we know, this is the first report of familial cardiomyopathy in Korea. In order to provide a better care to this rare disease, genetic and metabolic consultation as well as special laboratory facility should be readily available in Korea.