From its initial description to the present day, left ventricular noncompaction cardiomyopathy has been the subject of numerous studies and publications. In question as a real cardiomyopathy, left ventricular noncompaction can appear in isolation or in association with other cardiac malformations, genetic syndromes, and neuromuscular disorders. As a genetically heterogeneous disorder, it can be sporadic or familial, with an autosomal dominant pattern with variable penetrance most frequently observed. Different diagnostic criteria have been described through the years, first by using echocardiogram and later on by cardiac magnetic resonance. The lack of universally accepted diagnostic criteria has led to the condition being over-diagnosed in the general population. Differential diagnosis between real cardiomyopathy, epiphenomenon (phenocopy in the setting of loading conditions or even other cardiomyopathies), and physiological hypertrabeculation, like in the athlete's heart must be considered. Clinically it can present as heart failure, ventricular arrhythmias, and even sudden death, but it can also be asymptomatic during familial screening. The main prognosis factors are left ventricular dilatation, dysfunction, and fibrosis. There is no specific treatment. Familial screening is recommended and special recommendations in the case of athletes must be taken into account. In the present article, we review the myth and reality concerning main and more recent aspects of left ventricular noncompaction.