Mustard succeeded in the physiological correction of the circulation for transposition of the great arteries by redistribution of the pulmonary and systemic venous blood flow using pericardial baffle in the atrium. This procedure has become one of the most confirmative corrective operations for transposition. A six years old girl was performed mustard operation for complete transposition of the great arteries combined with hemodynamically insignificant ventricular septal defect in December 1979. The postoperative patient`s condition has been satisfactory and she is now enjoying a productive life. [KTCS 1981;2:161-167]