The ALLEGRA (Biosensors International) transcatheter heart valve is a self-expanding supra-annular bovine pericardial aortic valve. A new delivery system (IMPERIA™, Biosensors International) has been designed which allows the valve to be fully resheathed and repositioned in situ. The aim of this premarket study was to assess the safety and efficacy of transcatheter aortic valve implantation using the combination of the CE (Conformite Europeenne) marked ALLEGRA valve and the new IMPERIA delivery system. One hundred thirty-seven patients were enrolled in 11 centers from January to November 2023. There were 30 roll-in patients, 91 in the intention-to-treat (ITT) population and 16 with degenerated surgical aortic bioprostheses. The primary outcome was device success according to the Valve Academic Research Consortium-2 from discharge up to 7 days in the ITT cohort. Implantation of the ALLEGRA valve was successful in 136 patients (99.3%). There were no device embolizations and no patient required a second valve. Device success was achieved in 91.9% of the ITT cohort. At 30 days, all-cause mortality was 2.2% in the native aortic stenosis (AS) cohort and 0% in the valve-in-valve cohort. New pacemaker implantation was required in 12.4% (17/137). There was no patient prosthesis mismatch (PPM) in the 121 patients with native AS and moderate PPM in 2/16 valve-in-valve patients. This study confirms the safety and efficacy of transcatheter aortic valve implantation using the IMPERIA delivery system to implant the CE marked ALLEGRA transcatheter heart valve in patients with severe calcific native AS or a degenerated surgical aortic bioprostheses.