This study was conducted to investigate the effects of a no saline, a 2 ml and a 5 ml saline instillation prior to endotracheal suctioning on oxygen saturation in patients with pneumonia. The subjects in this study were 16 pneumonic patients with a tracheotomy tube, who had been admitted to the neuro-surgical intensive care unit at a university hospital in Seoul Korea. All three (0, 2 and 5 ml) saline instillation methods were applied to the 16 patients. The methods were randomly assigned to each patient. Each of the instillation methods was applied in a four-step sequence: 1) recording the level of oxygen saturation (baseline levels), 2) instilling normal saline, 3) supplying oxygen and suctioning, and 4) recording the level of oxygen saturation. The oxygen saturation was evaluated using pulse oximetry.