Background: Risk stratification models are increasingly important in the current clinical practice. Valvular heart surgery is quite a distinctive group as regard risk assessment. Two widely used risk factors are the updated European System for Cardiac Operative Risk Evaluation (EuroSCORE II) and the Society of Thoracic Surgeons (STS) risk score. We aimed to compare both scores regarding in-hospital morbidity and mortality. We also sought whether some other risk variables could be of value in predicting the postoperative outcome. Methodology: Two hundred and fifty five patients were included in the study. All patients underwent cardiac valve surgery with or without coronary artery bypass grafting. The data necessary for both EuroSCORE II and STS score were collected, in addition to data about proposed variables; left atrial (LA) diameter, Left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), and presence of left atrial thrombus. Discrimination of the each scoring system was assessed by the area under Receiver Operating Characteristics curve (AUROC), calibration was assessed by the Hosmer-Lemeshow test, where a P value > 0.05 was considered significant. For dichotomous variables, a correlation test was applied. Results: The overall in hospital mortality was 3.5%. EuroSCORE II and STS both provide equivalent discrimination and calibration in predicting mortality in Egyptian population. They also performed similarly in predicting morbidity. The performance of the EuroSCORE II was weaker in the higher risk group, and in predicting some morbidities. The proposed variables insignificantly predicted the mortality. Conclusion: EuroSCORE II and STS score are similar in predicting the outcome of cardiac valve surgery in Egyptian patients. Further studies are needed, with establishment of complete database, to develop a score which can cover for the areas of weakness of other scores when applied to Egyptian cardiac valve patients.