Double orifice mitral valve (DOMV) is an uncommon congenital heart defect. The isolated occurrence of this anomaly is very rare and, more often, is associated with another congenital malformation, dominated by atrioventricular canal defects (AVCD). Mitral insufficiency and/or stenosis may complicate this malformation. Treatment may be summarized as abstention, surgical valve repair, or valve replacement. In here, we report three cases with DOMV. The first patient was an 18-month-old boy who was operated for severe mitral valve stenosis and mild insufficiency (in 1980s), the second was a 47-year-old female, who was operated recently for mitral valve replacement (MVR) under cardiopulmonary bypass due to severe mitral valve insufficiency. This patient had been operated due to the secundum-type atrial septal defect in our institution previously. The last one, a 3-year-old boy, with DOMV and three papillary muscles, was on clinical follow-up because he had no symptoms.