Between Jan. and Oct. 1978, mitral valve Replacement had been performed on eight patients using porcine aortic valve mounted on flexible polypropylene or Egyloil wire and Dacron covered stent. Mitral valve replacement was performed on five, mitral valve replacement with tricuspid valve replacement on two, and mitral valve replacement with tricuspid valve annuloplasty on 1 patient using five Carpentier and five Hancock Xenograft. Overall operative deaths were 2 cases. All other 6 cases did well after surgery and improved. No systemic thromboembolism occurred without anticoagulant-No valve failure took place. The results are satisfactory.[KTCS 1978;4:428-432]