Dyspnea is the most common presenting symptom of patients with acute heart failure (AHF). Although dyspnea is an important target for treatment in clinical practice and clinical trials, there remains a lack of consensus on how to assess it. We describe and recommend to use absolute scales such the Likert 5-point or the Visual Analogue Scale rather than any comparator scale such as the Likert 7-point scale. We further recommend starting dyspnea measurements in sitting position and perform, if possible, similar measurements in lying position. The same set of measurements may be repeated as needed during the time course of disease and the treatment.