OBJECTIVES: To investigate respiratory and hemodynamic responses to deep breathing exercise (DBE) during the follow-up period in the intensive care unit after major head and neck surgery. STUDY DESIGN: Prospective study. SUBJECTS AND METHODS: Thirty-five patients were instructed to perform DBE every hour for 3 consecutive hours during the first postoperative day. The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2), oxygen saturation (SpO2), respiratory rate (RR), heart rate (HR), and mean arterial pressure (MAP) was recorded.RESULTS: DBE increased the PaO2/FiO2 ratio from 416.7 Ϯ 143.6 to 453.4 Ϯ 141.4 mm Hg and increased SpO2 from 97.4 Ϯ 1.9 to 99.2 Ϯ 0.9. DBE decreased the RR from 24.1 Ϯ 3.3 to 21.8 Ϯ 2.9 breaths/min (P Ͻ 0.05). No statistically significant difference in HR or MAP was observed after DBE (P Ͼ 0.05). CONCLUSION: DBE improves oxygenation after major head and neck surgery, without causing additional harmful hemodynamic effects.