The aim of this review is to emphasize the role of molecular biology in the diagnosis and therapy of major cardiomyopathies and cardiovascular risk factors. Therefore, we have underlined the genes responsible for or associated with these diseases while highlighting a role in the response to therapy (pharmacogenomics). Cardiovascular diseases and its related risk factors were divided into monogenic and polygenic forms. Monogenic forms are much rarer in clinical practice. However, polygenic forms along with most risk factors are of important clinical interest due to their high frequency in the general population. The added value of genetic testing is to provide an individual risk profile assessed in each patient and not only derived from epidemiological data. The prognosis of patients with the same risk profile, assessed using current clinical and medical history data, is often very different. An accurate prediction of the clinical course of cardiovascular disease in each patient will be the best therapeutic approach (tailored medicine) and will also result in a significant cost reduction for national healthcare systems (effective therapy).