Isolated noncompaction of the ventricular myocardium (INVM) is a rare cardiomyopathy resulting from a failure of normal endomyocardial embryogenesis and it has been categorized as a form of unclassified cardiomyopathy. The disorder is characterized by an excessively prominent trabecular meshwork with deep intertrabecular recesses. Although the disorder is sporadic, familial incidence may occur. Clinical symptoms and prognosis of INVM may differ markedly, and range from an asymptomatic course to a severe cardiac disability. The diagnostic method of choice for IVNM is echocardiography, which reveals multiple prominent trabeculations with deep intertrabecular spaces communicating with the left ventricular cavity in the middle and apical segments of the left ventricle. The authors report a case of INVM in a family in which three adult members (a brother and two sisters) were found to be affected by this disorder. They were all asymptomatic. The diagnosis of the disorder was made first in the 36-year-old brother by transthoracic echocardiography (TTE) and multidetector CT (MD CT), during the process of preoperative evaluation for surgical treatment of low back intervertebral herniated disc. TTE and MD CT showed similar and peculiar findings of INVM. Echocardiographic screening in all first-degree relatives of this patient, in order to identify asymptomatic patients, demonstrated INVM in two elder sisters.