BACKGROUND: Lung atelectasis are nonventilated parts of lung tissue and occur as a result of the collapse of the pulmonary parenchyma (alveoli). Various therapeutic procedures for inflating the collapsed pulmonary parenchyma, such as bronchial aspiration and/or standard recruitment maneuvers, are not always successful. CASE PRESENTATION: We report a case of a 23-year-old Croatian man with a parapharyngeal abscess on the left side of the neck with spreading of infection in the mediastinum and left side of the thorax and consequent major atelectasis of the left lung. The patient was mechanically ventilated. We decided to apply a new method in which a pulmonary artery catheter was placed (guided by bronchoscope) on the entrance to the lower left bronchus. The pulmonary artery catheter balloon was inflated to achieve bronchial closure. Using another respirator, we ventilated the affected lobe separately with continuously high pressure of 30 cmH2O. After 30minutes, we removed the pulmonary artery catheter from the lower left bronchus and placed it in the upper left bronchus and repeated the procedure. Our method allowed a significantly longer duration (30minutes) of continuously high pressure of 30 cmH2O separately to only one of the total of five lobes of the lungs while the other four lobes were simultaneously ventilated continuously with protective ventilation mode. CONCLUSION: Use of a pulmonary artery catheter and two respirators in our patient's case proved to be a successful method for recruiting the atelectatic lung while maintaining protective ventilation of the lung segments without atelectasis.