Lung cancer continues to be the leading case of cancer deaths in the United States. In patients with resectable non-small cell lung cancer, surgical resection is the treatment of choice. An accurate preoperative general and pulmonary-specific evaluation is essential as postoperative complications and morbidity of lung resection surgery are significant. After confirming anatomic resectability, patients must undergo a thorough evaluation to determine their ability to withstand the surgery and the loss of the resected lung. The measurement of spirometric indexes (ie, FEV(1)) and diffusing capacity of the lung for carbon monoxide (DLCO) should be performed first. If FEV(1) and DLCO are > 60% of predicted, patients are at low risk for complications and can undergo pulmonary resection, including pneumonectomy, without further testing. However, if FEV(1) and DLCO are < 60% of predicted, further evaluation by means of a quantitative lung scan is required. If lung scan reveals a predicted postoperative (ppo) values for FEV(1) and DLCO of > 40%, the patient can undergo lung resection. If the ppo FEV(1) and ppo DLCO are < 40%, exercise testing is necessary. If this reveals a maximal oxygen uptake (O(2)max) of > 15 mL/kg, surgery can be undertaken. If the O(2)max is < 15 mL/kg, surgery is not an option. This review discusses the existing modalities for preoperative evaluation prior to lung resection surgery.