Résumé : Thanks to a better knowledge of the genetic causes of many diseases and an improvement in genetic testing techniques, genetics has gained an important role in the multidisciplinary approach to diagnosis and management of congenital heart disease and aortic pathology. With the introduction of strategies for precision medicine, it is expected that this will only increase further in the future. Because basic knowledge of the indications, the opportunities as well as the limitations of genetic testing is essential for correct application in clinical practice, this consensus document aims to give guidance to care-providers involved in the follow-up of adults with congenital heart defects and/or with hereditary aortic disease. This paper is the result of a collaboration between the ESC Working Group of Grown-Up Congenital Heart Disease, the ESC Working Group on Aorta and Peripheral Vascular Disease and the European Society of Human Genetics. Throughout the document, the importance of correct counseling in the process of genetic testing is emphasized, indications and timing for genetic studies are discussed as well as the technical modalities of genetic testing. Finally, the most important genetic diseases in adult congenital heart disease and aortic pathology are also discussed.