To define risk and outcome of surgery in adults with congenital valve disease (CVD), experience between 2002 and 2005 with 371 CVD operations (288 males, aged 56 +/- 9 years) was compared with 2102 for acquired valve disease (AVD) (69 +/- 22 years, p = 0.02). Diagnosis included: bicuspid aortic valve (BAV), 337, s/p ToF repair, 11; atrio-ventricular valve dysfunction, 10; other, 13. Associated lesions were present in 259 patients (70% vs. 17%, p = 0.001): ascending aorta, 205; right ventricular outflow tract obstruction, 40; coronary artery, 34; mitral/tricuspid valve, 27; septal defect, 17; subaortic stenosis, 4; aortic arch, 4; other, 3. Fifty-two patients (14% vs. 2.5% AVD, p = 0.001) had undergone 75 prior operations (1.4/patient) and 14 (3.8% vs. 1.9% AVD, p = 0.04) required urgent/emergent surgery (endocarditis, dissection). Valve repair was done in 36 (10% vs. 3% AVD, p = 0.02) and replacement in 335: stentless solution (native, autograft, xenograft) was offered to 101 (29%) patients. In BAV, partial root replacement was associated in 63, complete in 77 and ascending aorta in 92. Three (0.8%) hospital deaths occurred (vs. 1.9% AVD, p = 0.2) due to endocarditis. Twenty-six patients (7.0% vs. 10.8% AVD, p = 0.003) experienced complications (cardiac, 7; neurologic, 6; respiratory, 5; renal, 3; sepsis/multiple organ failure (MOF), 2; hemorrhage, 8). Urgent/emergent surgery predicted hospital mortality (p = 0.001). During 5-year follow-up (average 2.6 +/- 1.8 years), there was one late cardiac death and three reoperations (98% free). Despite higher prevalence of associated procedures, reoperation and emergent indication, operative risk in CVD is lower than in AVD, possibly because of younger age. Stentless valve surgery, allowing normal life-style (e.g., exercise, pregnancy), is increasingly preferred.