Transcatheter aortic valve implantation has risen exponentially as a treatment modality for severe aortic stenosis in patients considered to be at high risk for or inoperable by conventional surgical aortic valve replacement. It has shown both survival and quality of life benefit in a randomized comparison to conservative (palliative) therapy in nonoperative candidates. Fundamental to its success is appropriate patient selection and a rigorous attention to procedural steps. In this article we will discuss the key issues pertaining to each of these factors.