Lung Ultra-Sound (LUS) can be very helpful at the diagnostic stage of COVID-19 pneumonia. We describe four clinical cases that summarize other helpful employment of LUS during the management of severe COVID-19 pneumonia with lung failure. LUS, together with clinical signs and arterial blood gases values, assists in guiding prompt clinical management of potential worsening of conditions. The monitoring of size and signs of aeration of consolidations is an important adjuvant in evaluating clinical evolution. The monitoring of LUS patterns can guide the management of non-invasive ventilation as well as the timing of CPAP weaning.