Acquired aortic stenosis (AS) resulting from calcification of the aortic valve is the most frequent acquired valve disease in Europe. Due to the increasing average life expectancy the population in the western industrial world is aging, and consequently the prevalence of AS requiring aortic valve replacement (AVR), particularly in older patients, is continuously increasing. However, the risk of conventional AVR with the use of sternotomy, cardiopulmonary bypass, and cardioplegic cardiac arrest is obviously higher in the elderly patient, in whom significant comorbidities may additionally pre-exist. Moreover, there is recent evidence that 30-40% of the patients with severe and/or symptomatic AS in Europe remain untreated and nearly half of them are considered "too sick" for surgery. Thus, there seems to be a role for less invasive treatment options, like transcatheter aortic valve implantation (TAVI) techniques, addressing an unmet patient and medical need. Today, an increasing number of different transcatheter heart valve devices for aortic valve implantation is coming up; however, so far only for two systems there is broad clinical experience with human implantations. The following article is aimed to describe the current transcatheter aortic valve implantation technique with full details of the procedural steps, both via the transfemoral and via the transapical access using the balloon-expandable SAPIEN transcatheter aortic heart valve device.