Background:The number of grown ups with congenital heart diseases (GUCHs) is steadily increasing.Aims:To analyze factors predicting early cardiac morbidity following cardiac surgery in GUCH at a tertiary care center.Setting and Design:Retrospective study at a multispeciality tertiary referral center.Methods:Between January 2004 and December 2014, 1432 patients ≥13 years of age (acyanotic defects: 843, cyanotic defects: 589) underwent surgery for congenital heart defects. Factors associated with early cardiac morbidity were analyzed.Statistical Analysis:Univariable and multivariable analysis of all factors affecting outcomes.Results:On multivariate analysis, previous sternotomy, aortic cross-clamp time >45 min, cyanosis, and emergency procedure were independent predictors of early morbidity with respective odds ratios (ORs) of 12.4, 3.6, 2.6, and 8.1. For more precise estimation, a risk score was generated. Taking the log odds with each of these four as respective weights, a score was generated. The variables were previous sternotomy (2.5), aortic cross-clamp >45 min (1.3), emergency procedure (2.1), and cyanosis (0.9), if the respective condition is present, zero otherwise. The score ranged from 0 to 4.5. The average value of the score based on the four variables was significantly higher in cases with morbidity (1.85 ± 1.17) vs. (0.75 ± 0.88), P < 0.001. Distribution of scores was significantly different between patients with and without morbidity. Sixty-seven percent patients without any morbidity had score <1 compared to 24.6% with morbidity. Only 0.9% patients without morbidity had score of ≥3 compared to 16.4% patients with morbidity. Compared with patients having score <1, patients with scores 1-2 had OR of 3.4, 2-3 had OR of 6.0, and >3 had OR of 48.7.Conclusion:GUCH can be safely operated when adequate caution is taken in the presence of independent predictors such as previous sternotomy, aortic clamp time >45 min, cyanosis, and emergency procedure.