Prone positioning is an adjuvant therapy used to treat COVID-19 pneumonia complicated by acute respiratory distress syndrome. However, prolonged pressure on facial skin at the level of the bony structures may be responsible for facial pressure ulcers. In the context of severe COVID-19 pneumonia, we hypothesized that hypoxemia, microvascular injury and thrombosis can increase the risk of pressure ulcers. We described two cases in order to emphasize the risk of facial pressure ulcers as a result of prone positioning, so as to discuss their physiopathology and highlight the importance of appropriate preventive measures.