Background: The number of adults with congenital heart disease (ACHD) is steadily rising due to increased survival rate and improved medical resources. Accordingly, more than 330,000 ACHD are currently living in Germany. Almost all of them require lifelong specialized medical follow-up for their chronic heart disease, often accompanied by residua, sequelae, or comorbidities. Primary care physicians (PCPs) are a crucial factor in directing patients to ACHD specialists or specialized institutions, but despite all efforts, the number of ACHD under specialized care is low, the lost-to-follow-up rate is high, and the morbidity and mortality is substantial. The present cross-sectional study was designed to systematically characterize the health care of ACHD from a patient perspective, including (I) use of medical care by ACHD, (II) medical counselling needs, and (III) perceived satisfaction with health care. Methods: The German-wide analysis was based on a 25-item questionnaire designed to address different aspects of medical status and health issues of ACHD from their own perspective, performed between May of 2017 and July of 2020. Results: A total of 4,008 ACHD (52% female; mean age 41.9±17.2 years) completed the questionnaire. The majority of ACHD (3,524, 87.9%) reported, that they consulted their PCP for non-cardiac health problems, and 49.7% (n=1,991) consulted their PCP also for medical problems associated with the underlying CHD. Almost all ACHD reported a need for medical advice concerning exercise capacity and daily life activities, occupational skills, pregnancy, rehabilitation, genetic counselling, insurance, and retirement. A total of 1,840 (45.9%) patients were not aware of the existence of certified ACHD specialists or centers. Moreover, 2,552 (67.6%) of those surveyed were uninformed about patient organizations for ACHD. Conclusions: The present study demonstrates that ACHD are largely uninformed about the ACHD care structures available nationwide, although the patients have a great need for specialized follow-up, advice, and care.