Hypertrophic cardiomyopathy (HCM) is often a familial disease in which the inheritance is autosomal dominant. The most devastating presentation of HCM is SCD in a presumed healthy person. The goals of family screening are to identify relatives with unrecognized HCM and to follow at-risk individuals for disease development and thus early identification of SCD risk factors. After confirmation of the HCM diagnosis, the patient is informed about the familial character of the disease, the high potential for familial transmission, and the possibility to perform genetic testing. The power of genetic testing in HCM lies in identifying family members carrying the genotype (G+) who are at risk for developing disease and excluding unaffected, genotype-negative relatives for further cardiac evaluation. In specialized cardio-genetic outpatient clinics, familial and genetic counseling is performed in close collaboration between cardiologists and clinical geneticists. Family members at risk are identified, and first-degree relatives are informed either via the patient or via direct communication. It is important that ramifications of genetic and/or cardiac testing, especially with regard to health and life insurance, are explained to the family members prior to analysis. G+ family members and family members of HCM families in which no (likely) pathogenic DNA variant is found are offered longitudinal cardiac evaluation by electrocardiogram and echocardiogram with variable intervals.