Objectives: To determine the incidence, timing and predictors of periprocedural valve dislodgment with the Medtronic Corevalve System (MCS). Background: Periprocedural valve dislodgment may occur during transcatheter aortic valve implantation (TAVI). Methods: Ninety-eight consecutive patients underwent TAVI with the MCS after a comprehensive baseline assessment including invasive angiography, echocardiography, and Multi-Slice Computed Tomography (MSCT). The invasive monitoring charts and angiographic studies of all TAVI procedures were reviewed to determine the incidence and timing of valve dislodgment. Results: Valve dislodgment occurred in 18 patients. Patients with valve dislodgment had a larger Aortic Valve Area (0.76 ± 0.25 cm2 vs. 0.61 ± 0.19 cm2, P = 0.007), lower mean transaortic gradient (37.65 ± 14.62 mm Hg vs. 47.11 ± 16.08 mm Hg, P = 0.03) and significantly less aortic root calcification (Agatston score median 1951 AU (IQR, 799–3103) vs. 3289 AU (IQR 2097–4481), P = 0.016). A lower aortic root calcium score (Agatston score < 2359 AU) was the single independent predictor for valve dislodgment (OR 3.10, 1.09–8.84). After valve dislodgment, the valve could be successfully retrieved and implanted in the proper anatomic location in all cases. Valve dislodgment was associated with a lower incidence of post-procedural AR ≥ 2 (11.1% vs. 34.6%, P = 0.05). There were no relevant procedural or clinical implications to valve dislodgment. Conclusions: The incidence of periprocedural valve dislodgment was 18% in these series. Less aortic root calcification appeared the single independent predictor. © 2011 Wiley Periodicals, Inc.