Background: The mean age of transcatheter aortic valve implantation (TAVI) patients is steadily decreasing. Aims: The aim of the study was to describe the characteristics, the indications for and the outcomes of TAVI in patients <70 years old. Methods: All patients undergoing TAVI (n=8,626) from the 18 participating centres between January 2007 and June 2020 were stratified by age (</>70). For patients <70, the indications for TAVI were extracted from Heart Team discussions and the baseline characteristics and mortality were compared between the two groups. Results: Overall, 640 (7.4%) patients were <70 (9.1% during 2018-2020, p<0.001); the mean age was 65.0±2.3 years. The younger patients were more often male, with bicuspid valves or needing valve-in-valve procedures. They had a higher prevalence of lung disease and diabetes. In 80.7% of cases, the Heart Team estimated an increased surgical risk and TAVI was selected, reflected by an STS score >4% in 20.4%. Five-year mortality was similar (29.4 vs 29.8%, HR 0.95, p=0.432) in the <70 and >70 groups. In the <70 group, mortality was higher for those referred for TAVI due to an increased surgical risk compared to those referred for other reasons (31.6 vs 24.5%, HR 1.23, p=0.021). Mortality was similar regardless of the STS stratum in patients judged by the Heart Team to be at increased surgical risk (32.6 vs 30.4%, HR 0.98, p=0.715). Conclusions: Use of TAVI in patients <70 is becoming more frequent. The main reason for choosing TAVI is due to an increased surgical risk not adequately represented by the STS score. The outcomes for these patients are similar to those for older TAVI patients. Dedicated trials of TAVI/SAVR in younger patients are needed to guide decisions concerning expansion of TAVI indications.