With recent advances in medical and surgical management, most patients with congenital heart disease (CHD) survive to reproductive age. Current guidelines recommend counseling about inheritance and transmission of CHD to offspring. We evaluated whether adult CHD patients recalled having received information about the inheritance of their CHD, patients' knowledge about inheritance and their concerns in this regard. A questionnaire was sent to 486 non-syndromic CHD patients aged 20-45 years. We received 332 useful questionnaires (response rate 68%). One-third (33%) of patients recalled receiving information about inheritance of CHD from their cardiologist, and 13% had consulted a clinical geneticist. Eight percent of patients who were considering having children estimated the recurrence risk for their own offspring to be 1% or lower, whereas one-fourth (25%) estimated it to be higher than 10%. According to our classification, 44% estimated the recurrence risk in a correct range of magnitude. Additional information about inheritance of CHD was desired by 41% of patients. Forty-two percent of patients considering having children reported concerns about transmitting CHD to offspring. We conclude that a substantial proportion of adult CHD patients lacks knowledge and desires more information about inheritance, indicating a need for better patient education. Current guidelines and/or their implementation do not seem to meet the needs of these patients. A dedicated program of counseling for adults with CHD has to be developed to optimize knowledge and satisfaction with information provision and to reduce or manage concerns regarding inheritance of CHD.