A 43-year-old female with a history of osteogenesis imperfecta was admitted to our hospital for congestive heart failure due to mitral valve regurgitation. The patient had suffered from bone fractures 5 times, dislocation of elbow and fingers 3 times since childhood, and subarachnoid hemorrhage 2 years before. She and her son have blue scleras. She was diagnosed with osteogenesis imperfecta type IA clinically. Echocardiography revealed severe mitral regurgitation and aneurysmal formation in the interatrial septum bulging to the right atrium. Mitral valve replacement and repair of the atrial septum were performed without any blood transfusion, but with rib fractures. Echocardiography showed no peri-valvular regurgitation at 1 year after the valve replacement. Cardiovascular disease is rarely associated with osteogenesis imperfecta, but its surgical mortality rate is high due to coagulation abnormality and fragile tissue. To reduce postoperative complications, precise classification of the disease and careful handling of the tissues during operation will be needed.