Background context Surgery for adult spinal deformity may require both an anterior and posterior approach in order to stabilize the spine and achieve the desired correction. These procedures can be associated with significant pulmonary complications, including atelectasis, pneumonia and respiratory failure. The etiology of some of the respiratory complications is clear: poor inspiratory effort from incision pain and previous pulmonary disease. However, for many patients the direct cause of these complications is not obvious. Purpose To delineate the incidence, severity and risks associated with pulmonary complications in the setting of major spine surgery. Study design/setting Retrospective chart review study of adult patients undergoing combined anterior-posterior thoracic, lumbar and sacral fusion spine surgery. Patient sample A total of 60 charts were reviewed for this study. Outcome measures Radiographic abnormalities correlated with clinical findings, postoperative need for ventilation and lengths of hospital stay were used as outcome measures. Methods Perioperative pulmonary complications were assessed for 60 patients with spinal deformities who underwent combined anterior-posterior thoracic, lumbar and sacral fusion over a 2-year period. Results One patient was eliminated from analysis because of multiple surgeries during his hospital course. Of the remaining 59 patients, 38 (64%) developed roentgenographic abnormalities. The most common radiographic finding was an effusion found in 66% of these patients, followed by atelectasis in 53%. Twenty-one percent (8 of 38) had infiltrates. Five (5 of 38) or 13% had evidence of partial or complete lobar collapse; in two bronchoscopy was required because of profound hypoxemia. Two patients had pneumonia requiring antibiotic treatment. All but two patients were extubated within 36 hours of surgery. They were kept intubated because of hemodynamic instability. There was no statistically significant difference in the group of patients with and without roentgenographic abnormalities with regard to age, weight, American Society of Anesthesiologists class, smoking history, pulmonary function test results, blood loss, perioperative blood and crystalloid requirement and length of surgery. Patients with radiographic abnormalities were more likely to have had invasion of their thoracic cavity (p=.02) and had a longer mean hospital stay of 13.5 versus 10.2 days (p=.009). Conclusion Radiographic abnormalities of the lungs are common after major spine surgery involving both an anterior and posterior approach, especially when the thoracic cavity is invaded. In view of the morbidity and longer hospital stay associated with such findings, close monitoring of pulmonary status with aggressive pulmonary toilet are indicated.