Aortic valve stenosis is a common disease. Despite this, the diagnosis may often be missed; a significant proportion of patients are still identified at post-mortem examination, and 5% of operations are performed at end stage. Unrecognized aortic valve stenosis is an important cause of anesthetic mortality. One reason for failing to make a diagnosis is that the clinical signs can be difficult to interpret due to the confounding association with arterial hypertension, coronary artery disease and systemic arteriosclerosis, potentially blunting the effects of aortic valve stenosis on the circulation. Moreover, most patients with aortic valve stenosis have a long asymptomatic period and may not seek medical attention. In patients with severe, symptomatic, calcific aortic valve stenosis, aortic valve replacement is the only effective treatment; much evidence suggests that it should be offered to patients regardless of age, after appropriate clinical evaluation. Doppler echocardiography plays a pivotal role in confirming the diagnosis of aortic valve stenosis in assessing the severity of the disease and, ultimately, in giving prognostically relevant information. Moreover, echocardiography is suitable for monitoring of disease progression and left ventricular function in these patients, and is of fundamental support for clinical follow-up. Accurate noninvasive quantification of aortic valve stenosis is, however, a technically demanding and time-consuming procedure, with several potential pitfalls. Considering the frequency and importance of aortic valve stenosis, a comprehensive echocardiographic study should be offered and carefully performed in all patients with noteworthy murmurs and repeated regularly (at appropriate time intervals), together with clinical review, in patients in whom aortic valve stenosis has been diagnosed.