Congenital heart diseases are currently treated in the pediatric age. However, a conspicuous number of patients requires treatment in the adult age. This study has been undertaken by members of the European Congenital Heart Surgeons Association with the aim of evaluating the impact of cardiac surgery in this particular age group. We have collected data from 1,247 patients who underwent 1,287 operations during a 5-year period between January 1, 1997 and December 31, 2001. Patients were divided into three groups: (1) palliative procedures (4.4%), operation performed to improve patients' clinical status without restoring normal anatomy or physiology; (2) repair (79.3%), operation performed to achieve an anatomic or physiologic repair with separation of the pulmonary from the systemic circulation (included in this group are also Fontan-type repair and one and a half ventricle repair); (3) reoperation (16.3%), all the reoperations performed after repair (either anatomic or physiologic). Hospital mortality (within 30 days) was 2.4% (range, 0% to 15.3% in different centers). Kaplan-Meier estimates shows a 94% survival at 4 years, which is higher for repair (95%) as compared with reoperations (92%) or palliations (88%). Surgery for congenital heart disease in the adult age is a safe, beneficial, and low-risk treatment that modifies patients' natural history by improving their clinical status.