A 67-year-old female patient underwent mitral valvuloplasty for mitral regurgitation due to the chordal rupture at the posterior commissure. Sliding commissuroplasty was made to avoid large annular plication. Carpentier's prosthetic ring (30 mm) was sutured to remodel the annulus and to reinforce repair. Postoperative Left ventriculogram revealed no regurgitation. Sliding commissuroplasty is effective for mitral regurgitation due to commissural chordal rupture.