Echocardiography is an essential tool in the evaluation of patients with suspected heart disease. It is noninvasive, portable, relatively inexpensive, and safe, with no exposure to ionizing radiation. Newer echo-based techniques such as three-dimensional (3D) echocardiography and strain imaging provide incremental value that is useful in patients with diabetes, particularly in high-risk patients or when subclinical disease is a concern. This chapter focuses on the use of transthoracic echocardiography (TTE) in patients with diabetes, particularly in the evaluation of coronary artery disease (CAD), diastolic dysfunction, and diabetic cardiomyopathy.