The ability to predict the degree of moderate AR after MVR is ofconsiderable importance, but relatively few studies have analyzedpredictors of changes in the degree of the aortic regurge .Up till now, noclear guidelines for management of patients with moderate aorticregurgitation in association with mitral valve replacement surgery.Patients and methods:That study was conducted in cardiothoracic surgery department in(National heart Institute) in Cairo prospectively. The period of followup ranges from six months up to one year started from April 2012 toApril 2013. Thirty patients were conducted in this study .all patients hadunderwent MVR .15 patients had a severe rheumatic mitral valvestenosis named group “A” and 15 had a severe rheumatic mitral valveregurge named group “B” .All cases are accompanied by moderateaortic valve regurge (grade II) .Assessment of degree of aortic regurgeand intracardiac dimensions was based on semi quantitative method usingDoppler echocardiography. All patients in the study were followed upafter 6 months and one year from operation by complete transthoracicechocardiography to detect degree of aortic regurgitation after mitralvalve replacement and to detect predictors of changes after MVRResults:Only 13.3% of group “A” the aortic regurge have progressed from (gradeII) to (grade III) while in group “B” only 6.7% of cases the aortic regurgehave progressed from (grade II) to (grade III). In group “A” leftventricular end diastolic dimension, left ventricular end systolicdimension, ejection fraction was increased and left atrium was decreased, while in group “B” left ventricular end diastolic dimension, leftventricular end systolic dimension, ejection fraction and left atrium weredecreased .These changes in dimensions did not affect the degree of theaortic regurge.Conclusion:Patients with moderate aortic regurgitation disease at the time of mitralvalve surgery rarely develop a hemodynamic significant aortic valvedisease over a midterm follow-up period. The minor progression in theAV disease over a midterm period of time and the increased perioperativeand long-term mortality and morbidity of a dual valve replacement do notjustify the performance of prophylactic AV replacement. This studyconcerned only with midterm follow-up but do not answer the questionsabout the longterm follow-up period.