Aortic stenosis (AS), the most prevalent valvular heart disease, significantly impacts the lives of older adults, with over 4% of octogenarians affected. This condition, characterized by the narrowing of the aortic valve, imposes excessive pressure on the heart, leading to a cascade of detrimental effects. These include the thickening of the heart muscle (left ventricular hypertrophy), impaired heart function, and ultimately, heart failure. While severe, untreated AS carries a grave prognosis, timely aortic valve replacement offers a promising avenue for reversing these detrimental effects and restoring a patient’s life expectancy to levels comparable to their healthy peers. Cardiac amyloidosis (CA), a condition characterized by the abnormal accumulation of protein deposits within the heart, affects a significant portion of the elderly population. While sharing some similarities with aortic stenosis (AS), CA carries a generally poorer prognosis. Recent studies have revealed a higher-than-expected incidence of AS and CA coexisting in patients. This co-occurrence presents unique challenges for diagnosis and treatment, as both conditions require distinct management strategies. The emergence of effective therapies for certain types of CA underscores the urgent need for improved diagnostic evaluation and optimized treatment approaches for patients with both AS and CA. In this chapter we comprehensively examine the pathophysiology and prevalence of CA in patients with AS and delve into the best practices for diagnosing and treating both conditions when they occur together. Our team has developed a novel algorithm for the management of aortic stenosis and cardiac amyloidosis.