Objective noninvasive measures of dyspnea in patients with acute heart failure are lacking. In this review, we describe lung ultrasound as a tool to estimate the degree of pulmonary congestion in patients presenting with acute heart failure and to monitor therapeutic efficacy. Serial semiquantitative measures of sonographic B-lines in acute heart failure patients can be converted to pulmonary edema scores obtained at admission and hospital discharge. These scores provide prognostic information for short-term clinical outcomes. Lung ultrasound has the potential to measure changes in pulmonary edema during acute heart failure management and improve risk stratification.