Background: - The first successful open heart surgery using extracorporeal circulation rntechnique was performed by John Gibbon in 1953 during an atrial septal defect closure. rnCardiovascular diseases (CVD) are group of diseases and injuries that affect therncardiovascular system. As the main cause of death on the planet, cardiovascular diseasern(CVD) in all its forms is an important public health problem. Most commonly CVD affectrnthe blood vessels of the heart and brain. In general they affect all people in both child andrnadulthood life. rnObjective:-The objective of this study is to assess characteristics and outcomes ofrnpatients who underwent open heart surgery from FEB, 2009 to DEC, 2020at cardiac center rnof Ethiopia. rnMethod:-Institutional based cross-sectional study design was conducted. rnSampling and Sample size determination: The sample size for the study wasrndetermined using single population proportion formula. And Simple random sampling rnretrospective chart review technique was used. rnRESULTS:-In this study a total of 320 patients were analyzed, from this 186 (58.1%)ofrnthe patients were female and 134(41.9%) were male. The majority of participants werernfound in the age group 6-18yrs 148(43.7%). The primary diagnosis from this study werernASD 54 (16.8%), VSD covered 42(13.1%), severe MR 40(12.5%). Only eight (2.5%) ofrnpatients had post-operative acute kidney injury and 5(1.6%) patients had post-operativernbleeding. the immediate overall mortality were 3(0.9%). rnConclusion and Recommendation: The present study had identified that more than halfrn58.1% of the patients were female. It also identified ASD the commonest CHDs followedrnby VSD. This study report that MV replacements were the most common valve surgery.rnOpen heart surgery can be performed with excellent outcome in cardiac center of Ethiopia.rnWe recommend that doing further research on associated factor for this outcome. Thatrnmay better to know which variable has association for good outcome .and also qualityrnimprovement and increase number of surgeons is good for doing all the surgeries by localrnteam.