Ultrasonographic scanning of the lung is gaining ever-growing recognition as a diagnostic and monitoring imaging technique. Its role in trauma assessment has already been established as an extension of the focused assessment of trauma with sonography for the diagnosis of pneumothorax. As more centers are discovering the advantages of ultrasound and conducting experimental and comparative studies, its use for diagnosing many other lung pathologies is becoming even more important. In-depth studies and innovative ideas are needed to explore the possibilities of this technology. We believe that, ultimately, the advantages for the patient will far outweigh the disadvantages of ultrasonography. Here, we review all possible applications of lung ultrasonography used thus far in Intensive Care Units, where a readily available and biologically non-invasive imaging technique may make the difference in diagnosis. In addition, we describe how the non-invasive nature of ultrasonography allows it to be used as a monitoring device of disease progression vs the healing process. We also provide a detailed explanation of the methods and materials necessary and a few indications towards unanswered questions in this field of research.