Advances in technology and imaging have expanded the range of tools for diagnosing aortic stenosis (AS). The accurate assessment of aortic valve area and mean pressure gradient is crucial to determine which patients are appropriate candidates for aortic valve replacement. Nowadays, these values can be obtained noninvasively or invasively, with similar results. Contrariwise, in the past, cardiac catheterization played a major role in the evaluation of AS severity. In this review, we will discuss the historical role of the invasive assessment of AS. Moreover, we will specifically focus on tips and tricks for properly performing cardiac catheterization in patients with AS. We will also elucidate the role of invasive methods in current clinical practice and their additional value to the information provided through non-invasive techniques.