This review summarizes recent reports on preoperative pulmonary evaluation focusing on the impact on outcome in thoracic and non-thoracic surgery. Data suggest that hitherto widely accepted pulmonary function tests do not predict perioperative complications. Therefore, they may not be considered alone to decide on the patient's operability. So-called prohibitive lung function parameters should no longer be used to deny a potentially curative lung resection. A more clinically oriented, interdisciplinary approach to severely compromised patients may be best suited to discuss and solve their problems.