Aims Genetic scientific knowledge is growing rapidly but how this affects clinical practice is unclear. We investigated the levels of knowledge, practical skills and clinical genetic practices of Dutch cardiologists. Methods and results A survey was designed to assess cardiologists' experience with genetic aspects of hypertrophic cardiomyopathy, self-reported genetic knowledge, and genetic skills in general and aimed at this disease. In addition, cardiologists' opinions on five possible measures for improvement were obtained. Study population: all Dutch cardiologists <f>(n=643)</f>. Median number of patients suffering from hypertrophic cardiomyopathy per cardiologist is five. Forty-one percent of respondents do not give information about genetics to all their patients. Cardiologists rarely initiate DNA tests for hypertrophic cardiomyopathy. Only 38% refer patients to clinical geneticists. Self-reported knowledge levels are low (average score 3.3–5.1, 0–10 scale). Cardiologists with an established working relationship with a clinical geneticist report significantly higher levels of knowledge. Clinical guidelines, education and improved collaboration with clinical geneticists are preferred. Conclusion Dutch cardiologists' genetic knowledge and clinical genetic practice levels are insufficient. As a result, clinical genetic care for patients with hypertrophic cardiomyopathy is poor. Improvements proposed include advancement of knowledge (education, professional guidelines) and structural measures (working relationships, multidisciplinary outpatient clinics). Collaboration of cardiologists and clinical geneticists is urgently needed to optimise cardiogenetic patient care.