Transesophageal echocardiography (TEE) is especially suitable for examination of prosthetic valves because of the proximity of the esophagus to the heart and absence of interference with lungs and ribs. This article reviews normal and abnormal morphologic characteristics of prosthetic valves such as spontaneous echocontrast, microbubbles, strands, sutures, vegetations or thrombus. Doppler echocardiographic characteristics of normal and pathologic prosthetic valve function and the management of prosthetic valve pathology is discussed. Physicians taking care of patients with prosthetic valves should be familiar with the characteristics of normal and abnormally functioning prosthetic valves.