Dyspnoea is a presenting symptom for patients with heart failure. It is often due to elevated left ventricular (LV) filling pressure but can be due to pulmonary disease or other non-cardiac reasons. While physical examination is useful, it has its limitations. Accordingly, non-invasive imaging has an important role in the diagnostic evaluation of patients with known or suspected heart failure. Echocardiography is usually the first test obtained and is used to determine LV volumes, ejection fraction and mass as well as right ventricular size and function, left and right atrial volumes, valvular lesions, and pulmonary artery pressures. Additionally, LV filling pressure can be estimated. A recent algorithm was published that depends on clinical, two-dimensional data and Doppler signals. The algorithm is accurate in patients with depressed and normal ejection fraction. There are other measurements that can be obtained as LV strain and diastolic strain rate and left atrial strain. These indices provide valuable insight into LV relaxation and filling pressure as well as left atrial function. Assessment of LV filling pressure has been evaluated most extensively in patients in sinus rhythm. However, it is also possible to assess LV filling and draw inferences about LV filling pressure in patients in atrial fibrillation, in patients with mitral valve disease and in patients with left ventricular assist devices. Left ventricular filling has been assessed by other imaging modalities, including cardiac computed tomography and cardiac magnetic resonance. While these other imaging modalities may be needed in some cases, echocardiography has the highest feasibility and validation, and the most practical application.