Aortic stenosis (AS) is a chronic, progressive disease predominantly affecting individuals aged over 60 years. Symptoms are the result of progressive left ventricular outflow obstruction, and herald rapid clinical decline and high mortality. Medical therapies for AS remain ineffective; operative valve replacement remains the only effective long-term treatment. We review clinical aspects of diagnosis and management of AS in adults, with attention to the natural history before and after valve replacement, assessment of suspected and established AS, and recommended management in general and in difficult clinical scenarios. We conclude with a series of 10 cases illustrating management of common, uncommon, and challenging clinical scenarios encountered at the University of Washington.