Increasing numbers of individuals are being referred to cardiogenetics outpatient clinics with potentially inherited arrhythmia (ARR) or cardiomyopathy (CM). To inform relatives at-risk, we ask index patients to distribute “family letters” containing information on the risks, possible genetic and other screenings, and preventive options. We assessed the responses to these letters in terms of referrals to a cardiologist and/or clinical geneticist. Fifty-six index patients were asked to distribute 249 family letters: 85 in the ARR group and 164 in the CM group. Within a mean follow-up period of 2 years (range 1–5 years) the number of relatives actually referred to the clinical geneticist and/or cardiologist was 57% (142 of 249). There was a significant difference (P < 0.01) between the ARR (80%) and CM groups (45.1%). To verify the results obtained from our files at the cardiogenetics department we sent a questionnaire to 52 index patients (response 50%). This showed that 23/26 (88%) index patients had distributed the letters to their relatives and that for 19/23 index patients one or more relatives had been screened. This is comparable with our files, which showed that 57% of relatives of index patients with a potentially inherited cardiac disease underwent screening, particularly in the ARR group. The actual response was underestimated because some relatives were investigated elsewhere or may still decide to be screened in the future. We conclude that distributing family letters is an effective way to inform and encourage relatives to undergo screening for high-risk inherited cardiac disease. Am. J. Med. Genet. © 2009 Wiley-Liss, Inc.