Acute heart failure is a life threatening condition requiring rapid diagnosis and treatment. However, the differentiation between heart failure and other conditions presenting with acute dyspnea is notoriously difficult in the emergency room. Point-of-care lung ultrasound is a simple, rapid and noninvasive technique directly visualizing fluid content in the lung as evidence for acute heart failure. A number of publications showed the diagnostic utility of lung ultrasound in the diagnosis of heart failure, but many open questions remain.