This study evaluated the effect of transcatheter aortic valve (TAV)-in-TAV on sinus hemodynamics and washout. With TAV becoming the standard procedure for aortic valve replacement and with the limited valve durability, a second intervention is necessary (TAV-in-TAV) after first TAV failure. Six arrangements of TAV-in-TAV were chosen for this study as follows: (1) Evolut 23 (Medtronic, Minneapolis, MN) in Evolut 26, (2) Evolut 23 in SAPIEN 3 23 (Edwards Lifesciences, Irvine, CA), (3) Evolut 26 in Evolut 26, (4) Evolut 26 in SAPIEN 23, (5) SAPIEN 3 23 in Evolut 26, and (6) SAPIEN 3 23 in SAPIEN 3 23. These TAV-in-TAV configurations were assessed in a pulse duplicator. Particle image velocimetry was performed. During systole, (1) the highest velocity was found with SAPIEN-in-SAPIEN (0.7 m/s) and the lowest was with Evolut 26-in-Evolut 26 (0.2 m/s); (2) the highest shear stress magnitude near the leaflet was with Evolut 23-in-SAPIEN (1.45 Pa) and the lowest was with Evolut 26-in-Evolut 26 (0.55 Pa); and (3) washout was almost equal in all sinuses of these cases (<2.5 cycles). This study shows that TAV-in-TAV is highly dependent on the valve that is originally implanted and the valve to be implanted. Washout is not significantly degraded after TAV-in-TAV compared with valve-in-valve and TAV replacement. Further studies are needed to optimize valve size and selection.