Background: Transcatheter aortic valve replacement (TAVR) and transcatheter mitral valve replacement expose operators to radiation. These procedures differ primarily in whether they are performed via a transfemoral (TF) or an alternative access (AA) approach. This study compared operator radiation exposure during transcatheter valve implantation when performed via a TF vs an AA approach, when performed in a catheterization lab vs a hybrid operating room (OR), and investigated the potential benefit of disposable shielding. Methods: Dosimeters were worn during TAVR-TF (n = 50) and TAVR-AA (n = 31) procedures by operators. All TAVR-AA procedures were performed in a hybrid OR and TF procedures were performed in either catheterization labs (n = 16) or a hybrid OR (n = 34). Disposable radiation shielding pads (RADPAD; Worldwide Innovations and Technologies, Inc, Kansas City) or a placebo were added in a randomized, blinded fashion. Results: Team radiation exposure was higher after TAVR-AA vs TAVR-TF (median 15.1 mRad [interquartile range: IQR 8.6, 32.4] vs 5.5 mRad [IQR 2.4, 9.8], P < .001). TAVR-TF procedures required the same amount of fluoroscopy time regardless of where they were performed (20.3 ± 7.4 min in hybrid OR vs 19.0 ± 6.4 min in catheterization lab, P = .55). However, radiation exposure for TAVR-TF remained higher when performed in a hybrid OR (median 9.0 mRad [IQR 4.5, 11.9] vs 2.2 mRad [IQR 1.3, 2.8], P < .001). Radiation exposure was greatest for TAVR-AA (median 15.1 mRad [IQR 8.6, 32.4]). The use of RADPAD did not decrease radiation exposure (median 9.0 mRad [IQR 4.5, 14.7] vs 9.4 mRad [IQR 2.8, 19.5], P = .82). Conclusions: Procedures performed in the hybrid OR were associated with higher operator radiation exposure. In comparison with the TF approach, AA cases had the highest levels of operator radiation. This is particularly important in cases of transcatheter mitral valve replacement that can only be done via an AA approach. The use of disposable radiation shielding in this series did not attenuate operator radiation exposure. Radiation shielding within hybrid ORs should be scrutinized in an effort to remain on par with that found within catheterization labs.