We sought to analyze outcomes of patients with degenerated surgically implanted bioprosthetic heart valves undergoing valve-in-valve (viv) transcatheter aortic valve implantation (TAVI).Redo cardiac surgery for degenerated bioprosthetic heart valves is associated with increased risks, particular in elderly patients with comorbidities. For these patients, TAVI may be an attractive, less invasive treatment option.Data from 47 patients age 64 to 97 years (logistic euroSCORE: 35.0 ± 18.5%) undergoing transfemoral (n = 25) or transapical (n = 22) viv-TAVI for failed bioprosthetic aortic valves 113 ± 65 months after initial surgery at 9 clinical sites in Germany and Switzerland were analyzed.Valve-in-valve TAVI was technically successful in all patients, with 2 patients requiring bailout implantation of a second TAVI prosthesis for severe regurgitation during the procedure. There was 1 procedural death as the result of low-output failure. Valvular function after viv-TAVI was excellent with respect to valve competence, but increased transvalvular gradients ≥20 mm Hg were noted in 44% of patients. Vascular access complications occurred in 6 (13%) patients, and 5 (11%) patients required new pacemaker implantation after viv-TAVI. Renal failure requiring dialysis occurred in 4 (9%) patients. Mortality at 30 days was 17% (1 procedural and 7 post-procedural deaths), with 3 of 8 fatalities the result of non-valve-related septic complications.Valve-in-valve TAVI can be performed with high technical success rates, acceptable post-procedural valvular function, and excellent functional improvement. However, in these predominantly elderly high-risk patients with multiple comorbidities, viv-TAVI was associated with 17% mortality, often because of septic complications arising in the post-operative phase.