Hacettepe University Faculty of Medicine Department of Cardiovascular Surgery; data of 413 patients under 18 years old who had congenital heart surgery were evaluated between 01.01.2011-30.10.2012 and risk scorings were made by "RACHS-1 (Risk Adjustment in Congenital Heart Surgery)", "Aristotle Basic Complexity Score (ABS)" and "Aristotle Comprehensive Complexity Score (ACS)" systems used in evaluation of the risk of mortality and morbidity in congenital heart surgery. Data obtained were compared by Mann-Whitney U test and how effective these systems were in evaluating mortality and morbidity and their superiorities over each other were examined. Following the research, it was observed that all three systems were effective in evaluating mortality and morbidity; the most successful of them in foreseeing the event was the ACS system, ACS system was followed by RACHS-1 system and ABS system was the most incapable of these in foreseeing the event. It was seen that in detecting time related mortality, rating of these tests changed, RACHS-1 system detected the time related mortality best. It was also seen that with RACHS-1 system, a previously evaluated concept, it was possible to determine morbidity.