OBJECTIVES: To assess the safety and efficacy of first-line transcatheter aortic valve implantation (TAVI) in patients presenting with acute decompensated aortic stenosis (ADAS). BACKGROUND: ADAS is common and is often treated medically or using balloon aortic valvuloplasty in the first instance. This temporizing measure results in suboptimal outcomes. In the current era, TAVI provides an alternative option. METHODS: Consecutive patients who had either a TAVI for ADAS or electively were included in the study. The primary outcome was procedural and 30-day mortality and hospital length of stay (LOS). Secondary outcomes included 1-year mortality and procedural complications. RESULTS: Of note, 893 patients (mean age 83 ± 7, 50.5% male) underwent TAVI (19% ADAS, 81% elective). ADAS patients were more unwell with worse echocardiographic parameters than elective patients. ADAS patients of 55.9% were known to have significant aortic stenosis prior to their decompensation. Procedural mortality was not different between the ADAS and elective cohorts (1.2 vs. 0.7%; p = .62). The ADAS cohort had a higher 30-day mortality (5.3 vs. 1.1%; p = .002) and longer LOS (31.9 ± 20.7 days vs. 6.1 ± 6.5 days; p < .001). Multivariate analysis identified acute kidney injury and ADAS as significant predictors of 30-day mortality. CONCLUSIONS: TAVI for ADAS is safe and effective with procedural outcomes similar to elective patients. However, compared to elective patients, they have worse physiological baseline features, poorer prognosis at 30 days, and longer hospital admissions. Majority of patients who presented with ADAS were known to have AS prior to admission.