In 14 patients, kyphoscoliotics, at the time without cardiorespiratory diseases, of average age 28 years ± 17 (range 12–64), the average values for the vital capacity was 79.6 ± 21.2% (range 49–125), for the Tiffeneau Index was 77.9% ± 10.3% (range 56–91), for the RV/TLC ratio was 39.6% ± 10.8% (range 18–56), for the MEF 25 was 2,192.8 ± 732.1 ml/s (range 1,300–3,800), for the MEF 50 was 3,689.3 ± 1,310.9 ml/s (range 1,750–5,500). The average value for the PaO₂ was 90.3 ± 8.3 mm Hg (range 75–109), and for the PaCO₂ 35.3 ± 4.66 mm Hg (range 27.8–46). The average value for the alveolar-arterial gradient of O₂ was 11.96 ± 7.37 mm Hg (range 0.74–27.94) and for the arterial-alveolar gradient of CO₂ 2.30 ± 2.41 mm Hg (range 0.22–9.98). The average value for the CO transfer was 20.06 ± 6.84 ml/min/mm Hg (range 8–31.4). As the angle of scoliosis and the age of the subject increase, the vital capacity and the Tiffeneau Index decrease, the RV/TLC ratio and the respiratory rate increase, the MEF 25, the MEF 50, the PaO₂, and the transfer of CO decrease, while PaCO₂ increases. The alveolar-arterial gradient of 0₂ and the arterial-alveolar gradient of CO₂ increase as the angle of scoliosis increases. The data so obtained show, therefore, that in kyphoscoliosis a restrictive type of respiratory dysfunction appears, along with hypoxemia due to alveolar hypoventilation and disturbances in diffusion and in the ventilation-perfusion ratio.