Reintervention of a mitral degenerated bioprosthesis has a high surgical risk, especially in elderly patients with multiple comorbidities. We report a 74 years old female with two previous cardiac surgical procedures and a new structural mitral bioprosthesis deterioration with severe mitral regurgitation. Considering her high-surgical risk, a fully percutaneous treatment was performed with a balloon-expandable aortic valve in mitral position (valve-in-valve) through a transseptal approach with a favorable outcome. This technique is an attractive and effective option with a relatively low rate of complications that could solve this challenging and complex disease.