A 76-year-old woman required aortic valve replacement due to severe aortic stenosis. She had a huge thyroid cancer, which invaded the innominate and left internal jugular veins. We planned a two-stage operation : the first involved aortic valve replacement ; and the second involved operation of the thyroid cancer. To avoid median sternotomy, we adopted the right parasternal approach. A 7-cm right parasternal skin incision was made. The third and fourth costal cartilages were cut and bent into the right thoracic cavity, without removal of the ribs. The postoperative course was uneventful, and second operation was performed via the median sternotomy approach on postoperative day 53. The right parasternal approach can be used as an alternative when sternotomy is unsuitable in cases of aortic valve replacement.