Aortic root enlargement procedures are used to implant a larger aortic valve. Median sternotomy may cause complications, including dehiscence and mediastinitis. Cosmetic concerns of median sternotomy are minimized with minimally invasive approaches. Although the subaxillary vertical incision is not a conventional minimally invasive approach, it is favored since the incision is hidden in the subaxilla, and the thoracic integrity is preserved. Herein, we demonstrated that Y-incision aortic root enlargement can be safely performed in double valve replacement through subaxillary vertical thoracotomy in a 63-year-old female patient with better cosmetic outcomes and without compromising the replaced mitral valve.