Echocardiography – the investigation of the heart with ultrasound – is the most frequently used cardiac imaging modality. Transthoracic echocardiography is a powerful tool to evaluate the structure and function of the heart. Further evaluation is possible with transoesophageal echocardiography. However, its higher resolution and image quality are accompanied by a small risk of complications. Stress echocardiography allows identification of patients with significant coronary artery disease with high sensitivity and specificity. The aim of this article is to outline the information that echocardiography can provide and the clinical situations where it is indicated. Further advanced applications such as contrast and three-dimensional echocardiography will also be discussed.