Echocardiography is noninvasive, allows real-time visualization of the heart, and can be performed serially without harmful biologic effects. It is also relatively inexpensive compared with other diagnostic modalities used for cardiac transplant rejection surveillance, such as cardiac biopsy, computed tomography, and magnetic resonance imaging. It is free of the potential complications associated with cardiac biopsy, such as accidental disruption of cardiac valves or chordae tendineae, ventricular septal perforation, introduction of bacteria, and the difficulty of obtaining adequate sampling for effective diagnosis as a result of formation of scar tissue. Unlike biopsy, echocardiography does not cause the patient anxiety and discomfort or use many physician and instrument or laboratory resources. Because the results of echocardiography are available within minutes compared with the hours usually needed for biopsy results, it allows prompt decisions regarding patient clinical care and treatment. In our work to date, echocardiography has not replaced the cardiac biopsy in surveillance of rejection in the cardiac transplant patient, but rather has become a useful adjunct to it. When echocardiographic findings indicate changes characteristic of rejection, biopsies are performed earlier, leading to earlier diagnosis and treatment. Furthermore, when echocardiographic findings are stable and negative for rejection, the number of routine cardiac biopsies performed can be reduced. This article discusses the use of echocardiography in surveillance of the cardiac transplant patient and the ability of echocardiography to augment the biopsy and clinical regimens in assessing cardiac allograft rejection.