The aim of preoperative lung function analysis and diagnostic cardiology is to identify patients with an increased risk of complications and to best inform the patients about treatment options and risks so that an informed treatment decision can be made. The identification of patients at increased peri-interventional risk by preoperative physiological diagnostics also forms the basis for further developments and improvements of interventions and intervention techniques in order to reduce the risk of complications. The acquisition of a detailed medical history, a thorough physical examination, and the diagnosis using ECG and spirometry may provide the first evidence for the presence of relevant comorbidities. In elective surgery a detailed preoperative evaluation of comorbidities must be done. The association of age and operative mortality is not only due to age alone, but also involves the spectrum of comorbidities. The algorithms for Germany are based on the "S3 Guidelines of the German Society of Pneumology of 2010". Both German and international guidelines recommend the discussion of each case before lung resections in an interdisciplinary case discussion with thoracic surgeons, oncologists, radio-oncologists and pulmonologists. Patients of advanced age should always be subjected to an extended preoperative cardiopulmonary investigation.