Flail chest is a potential emergency which occurs when three or more ribs are fractured on two or more sites. It is a common type of injury caused by blunt trauma to the chest, as seen in traffic accidents, violence and falls. It is more common in men, especially younger ones. This occurence generates an unstabilised piece of the chest wall, which moves paradoxically, in an opposite way compared to the rest of the chest wall during the inhalation and exhalation. This is a major symptom, along with pain and dyspnea. The most common complication and adjacent pathology is the lung contusion, but atelectases, infections, pneumothorax, respiratory failure and others can also occur. Flail chest is diagnosed via the clinical examination and imaging techniques. The patient usually has to be situated in an ICU. Therapy can consist of stabilisation, analgesia, endotracheal intubation and mechanical ventilation, thoracotomy and fixation of the ribs, pulmonary hygiene and physiotherapy. Speaking long –term, this type of injury has a lot of complications, and causes a lot of disability and death. In the future, we should standardize therapy protocols and make them better.