This article examines the use of transesophageal echocardiography (TEE) in the assessment of prosthetic heart valves. A summary of the commonly used artificial valves and their physiologic regurgitant flow patterns, as identified by color Doppler imaging, is presented. The hemodynamic evaluation of prosthetic valve stenosis using Doppler techniques is reviewed, and the diagnostic utility of TEE in identifying the complications of cardiac prostheses is discussed.