Between April 1989 and March 1994, sixteen patients underwent the reoperation for valvular disease. In early years, complete heart dissection performed during operation (group A, n = 7). And recently, minimal necessary dissection was applied (group B, n = 9). In group B, dissection was limited to the ascending aorta, both vena cavae and right upper pulmonary vein. If the adhesion would be dense, pleural cavity would be widely opened and both caval cannula and left atrial vent tube would be cannulated through pleural adhesion. Operation time of group B was significantly decreased in comparison with group A. (group A: 569 +/- 91 min, group B: 347 +/- 65 min, p < 0.01). Post-operative course of group B was considered to be better than group A. These result suggested that minimal necessary heart dissection would be extremely effective during the repeated valvular surgery.