Annular stabilization in a newly-developed plication technique is discussed. Patients suffered degenerative mitral valve prolapse with chordal rupture restricted to the middle scallop of the posterior leaflet. Using a newly developed technique (n = 32), a pericardial strip was tightly anchored to the bilateral trigones and posterior annulus, which was folded by Gerbode plasty. Progression of mitral regurgitation after surgery was seen in six cases (two grade 1; four grade 2). Conventional plication techniques were used in 102 patients. Progression of mitral regurgitation after surgery was seen in 41.1% of patients (to grade 1 in 5.9%, grade 2 in 17.6%, grade 3 in 17.6%); this resulted in reoperation due to plication breakdown of the Gerbode plasty (5.9%) or either chordal rupture or annular dilatation (9.8%). The newly developed annuloplasty technique may be useful in stabilizing the mitral annulus after Gerbode plasty.