Congenital mitral valve (MV) dysplasia is a relatively rare and highly complex cardiac disease. We sought to provide a comprehensive analysis of the current surgical techniques for treating mitral valve insufficiency and the results of mitral valve repair at our institution. Between 1972 and 2017, 104 consecutive patients underwent surgical repair of congenital MV dysplasia-insufficiency at our institution. Among these, 59 patients presented with MV insufficiency (or prevalent MV insufficiency) and were part of the study. There was 1 early (1.7%) and 1 late death (1.7%). Survival at 5, 10 and 20 years was 98%, 98% and 94%, respectively. Eight patients (14%) required MV replacement for residual significant MV insufficiency. Freedom from re-intervention for MV dysfunction at 5, 10 and 20 years were 89%, 84% and 79%, respectively. Surgical techniques for treating mitral valve insufficiency must be tailored for each patient with the main goal of achieving a proper valve function, rather than a "normal" anatomy. The mechanism underlying valve dysfunction in congenital mitral valve insufficiency is multifactorial and requires the application of a variety of surgical techniques in each case.