More than two decades have elapsed since the discovery that sarcomere gene defects cause familial hypertrophic cardiomyopathy (HCM). Since then, genetic testing in HCM has developed, and become an important tool in clinical practice for diagnosis and prognosis overall in the Western countries. However its practical benefits are still understimated and clinicians often question about cost-effectiveness of genic testing in HCM patients and their families. This resistance is in contrast with considerable evidence supporting the role of genetics in tailoring management for HCM patients. Several current clinical uses of genetic testing in HCM, ranging from diagnosis in ambiguous situations, identification of disease phenocopies and HCM complex genotypes and confirmation of inherited disease in family members are reviewed. In the near future it is hoped that next generation sequencing will provide further diffusion of genetic testing in HCM and improvement in care.