Abstract Rates of successful surgical repair and life expectancy for patients with congenital heart disease have increased dramatically in recent decades. Thanks to advances in diagnosis, treatment, and follow-up care, an ever-increasing number of individuals with congenital heart disease are reaching advanced age. The exposure to cardiovascular risk factors during their lifetime is modifying the outlook and late clinical trajectory of adult congenital heart disease (ACHD). Their disease burden is shifting from congenital to acquired, primarily atherosclerotic cardiovascular disease (ASCVD) with worrisome consequences. In addition, the complex background of ACHD often curbs appropriate preventive strategies by general practitioners or adult cardiologists. Comprehensive guidance for the prevention and management of acquired heart disease in ACHD patients is currently not available, as this topic has not been covered by the European Society of Cardiology (ESC) guidelines on cardiovascular disease prevention or the ESC guidelines for the management of ACHD. In this document, a state-of-the-art overview of acquired heart disease in ACHD patients and guidance on ASCVD prevention for both ACHD specialists and non-ACHD cardiologists are provided. The aim is to provide a clinical consensus statement to foster the development of a sustainable strategy for the prevention of ASCVD in a practical and simple-to-follow way in this ever-growing cardiovascular cohort, thus reducing their cardiovascular burden.