In our study, one hundred and twenty three children with mitral valve diseases were operated upon by mitral valve repair using various techniques and methods of repair.Those children were operated and followed-up during the period from January 2007 and June 2012 at Atfal Masr insurance hospital (ex. Abulresh Altalba) at center of paediatric cardiac surgeries preoperatively, early postoperative (122 cases excluding one case of immediate postoperative mortality) and midterm postoperatively at 6 months(120 cases excluding 2 early mortalities and one early reoperation revision by replacement) and at 12-24 months(100 cases excluding also cases from January to June 2012).