This study aimed to assess the prognostic value of soluble ST2 (sST2) for risk stratification in patients undergoing transcatheter aortic valve implantation (TAVI). In 461 patients undergoing TAVI, sST2 was determined at baseline and categorized into quartiles. An optimum cutoff of 29 ng/ml was calculated. Primary end point was 1-year all-cause mortality. Results were validated in an independent cohort. Patients with sST2 >29 ng/ml had an increased 30-day (9.7% vs 4.6%, p = 0.043) and 1-year mortality (38.1% vs 21.8%, p = 0.001). In accordance, patients with N-terminal pro-brain natriuretic peptide (NT-proBNP) >8145 pg/ml revealed a comparable 30-day mortality (7.9% vs 4.7%, p = 0.189) and 1-year mortality (39.5% vs 21.0%, p <0.001). In univariate regression analysis, sST2 and NT-proBNP were associated with increased mortality risk. In multivariate regression analysis, independent predictors of mortality were logistic EuroSCORE, chronic renal failure, left ventricular ejection fraction, and sST2. In receiver operating characteristic curve analysis, sST2 did not provide incremental prognostic information beyond that obtained from surgical risk scores such as the STS-PROM or NT-proBNP. Similar findings could be achieved in an independent validation cohort. In conclusion, sST2 is independently associated with adverse outcome after TAVI but was not superior to NT-proBNP or surgical risk scores for the prediction of postprocedural outcomes.