Patients with respiratory distress present a frequent and challenging dilemma for emergency physicians (EPs). The accurate diagnosis and treatment of the underlying pathology is vitally important in these sick patients to ensure the best outcome and minimise harm from unnecessary treatments. Within the last decade, studies have shown lung ultrasonography (LU) to be valuable in the accurate diagnosis of a variety of lung pathologies, including cardiogenic pulmonary oedema, pleural effusion, pneumothorax, haemothorax and pneumonia. However, despite advances in techniques and the evidence for the use of LU in the diagnosis of respiratory pathology, it remains poorly understood and rarely used by EPs. This clinical review article provides an overview of LU and its relevance as a diagnostic aid to the detection of respiratory pathology in the Emergency Department (ED).