The aim of this study was to evaluate which parameters of preoperative spirometry and cardiopulmonary exercise test are the best predictors of postoperative morbidity and mortality in patients with bronchogenic carcinoma.Ninety seven patients were prospectively and consecutively examined. All patients had preoperative maximal exercise test and dynamic spirometry. Postoperative complications and causes of death were registered. Logistic regression was used and models explaining the relationship between preoperative variables and postoperative complications and deaths were constructed.We found significant differences in preoperative maximal workload and carbon dioxide output between groups, with and without cardiopulmonary-related complications, but not in spirometry variables. Logistic regression showed maximal workload to be the only predictor of cardiopulmonary complications. Maximal oxygen uptake was predictive of cardiopulmonary deaths. Maximal oxygen uptake and forced expiratory volume were predictive of postoperative complications. A maximal oxygen uptake <50% predicted was associated with high risk of death from cardiopulmonary causes. Kaplan-Meier survival curves showed that maximal oxygen uptake was correlated to long-term survival, while spirometric variables were not.Exercise testing can be used in the preoperative evaluation of patients with nonmetastatic bronchogenic carcinoma. A combination of the results of variables from spirometry and exercise testing is proposed to be used as a preoperative criterion for operability. Eur Respir J 1997; 10: 1559-1565 Carcinoma of the lung is one of the most common causes of death due to cancer in men, and is increasingly common in women. Some 900,000 new cases are reported worldwide every year [1]. The prognosis in untreated cases is poor, and at present the major curative treatment modality for non-small cell carcinoma is resection. The removal of lung parenchyma from patients, who are usually smokers with compromised cardiovascular or pulmonary status, may lead to cardiopulmonary failure or death. Many variables have been used to assess the risk of postoperative complications, but it is not clear which of these parameters in preoperative pulmonary function testing are the best predictors of the operative outcome. Many centres recommend operation without additional testing in patients with a forced expiratory volume in one second (FEV1) >2.0 L or 60% of predicted and a diffusing capacity >60% pred [2][3][4][5][6]. If these requirements are not met, a perfusion or ventilation scan is performed, and the predicted postoperative FEV1 (FEV1,ppo) is estimated. The accuracy of these methods is proven [7][8][9][10][11] and it seems generally accepted that a FEV1,ppo of 0.8-1.0 L or 30% pred represents the lower limits of acceptable risk [4][5][6][12][13][14][15][16][17]. Some recommend different limits for different resections [18]. In spite of this consensus for identifying patients at risk, about 30% develop cardiopulmonary complications with a 30 day mortal...