Transcatheter valve implantation is becoming an alternative to conventional surgical valve replacement in patients at high surgical risk. While experience and acceptance with transcatheter techniques increased rapidly, transcatheter valve implantation within failing bioprostheses has emerged as a new concept (valve-in-valve implantation). Currently, the majority of prostheses implanted in patients are bioprosthetic valves that are expected to degenerate over time. Valve-in-valve implantation provides great utility in high-operative-risk patients since the mortality risk for reoperation can be significantly higher than for first-time isolated valve replacement. Although two current devices are CE Mark approved in Europe for implantation within native valves, off-label clinical implementation of valve-in-valve have been described in numerous case reports. In this article, we provide an overview of transcatheter valve implantation in failing bioprostheses with an emphasis on the aortic position.