Background: Paravalvular leakage (PVL) is a frequent complication after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS), and is related to adverse prognosis. We aimed to investigate whether aortic valve calcium volume (Ca-Vol) measured by preoperative cardiac computed tomography (CT) had a predictive value for PVL. Methods and Results: We analyzed consecutive 43 patients underwent TAVI using third-generation self-expandable valve (Evolut PRO ®︎ ) for severe AS with tricuspid valve. Among 43 patients, PVL was detected in 8 cases (18.6%) after TAVI. PVL was defined as moderate or severe regurgitation determined by transthoracic echocardiography. We analyzed preoperative cardiac CT (Fig 1), and measured total Ca-Vol in aortic valve and Ca-Vol in each cusp (non-coronary cusp [NCC], right-coronary cusp [RCC], and left-coronary cusp [LCC]). The threshold of CT value for calcium structure was determined at 500 Hounsfield Units as previously reported. Total Ca-Vol was significantly higher in the PVL group than in the non-PVL group (3.9 ± 2.8 vs. 2.1 ± 1.0 ml, P = 0.004). Ca-Vols in each cusp were also significantly higher in the PVL group than in the non-PVL group (NCC, 1.5 ± 1.0 vs. 0.8 ± 0.4 ml, P = 0.004; RCC, 1.2 ± 1.1 vs. 0.6 ± 0.3 ml, P = 0.007; and LCC, 1.1 ± 0.8 vs. 0.7 ± 0.4 ml, P = 0.021). Univariate logistic regression analysis for PVL indicated that total Ca-Vol and NCC Ca-Vol were predictors for PVL (total Ca-Vol, OR 2.0, 95% CI 1.0-4.1, P = 0.042; NCC Ca-Vol, OR 5.1, 95% CI 1.2-22.2, P = 0.031). By the receiver operating characteristic curve analysis of Ca-Vol for prediction of PVL, the optimal cut off values were 2.3 ml of total Ca-Vol and 0.8 ml of NCC Ca-Vol (Fig 2; AUC = 0.75 and 0.78, sensitivity 0.75 and 0.88, specificity 0.63 and 0.54, respectively). Conclusion: Total Ca-Vol and NCC Ca-Vol were significant predictors for PVL after TAVI. Ca-Vol can be measured routinely with preoperative CT and might be useful in predicting PVL.