Objective: To define risk factors for postoperative morbidity and mortality in patients undergoing standardised laparotomy/gastrectomy or thoracoabdominal resection for carcinomas of the stomach, oesophagus, and oesophagogastric junction. Design: Prospective open study. Setting: University hospital. Sweden. Subjects: All 213 patients operated on for carcinoma of the stomach, oesophagus, or oesphagogastric junction between January 1983 and June 1990. Interventions: Laparotomy gastrectomy (n = 132) or thoracoabdominal resection (n = 81). Main outcome measures: Postoperative morbidity and mortality. Results: 8 Patients died after laparotomy/gastrectomy, and 10 after thoracoabdominal resection. Complications were more common after thoracoabdominal resection (101 in 81 patients) than after laparotomy gastrectomy (108 in 132 patients). The most common complication in both groups was pneumonia (29 132. 22%, compared with 22/81, 27%), but this could be predicted only in the group that underwent thoracoabdominal resection. Significant risk factors in this group were: an abnormal chest radiograph preoperatively (p = 0.0007), a high risk predicted by the anaesthetist (p = 0.005), and signs of obstruction on spirometry (p = 0.002). In the thoracoabdominal group a history of pulmonary disease. the patient's age, and general physical performance assessed by the exercise test significantly predicted a high risk oi postoperative death. Risk profile curves For mortality were generated for patients aged 55, 65, or 75 years with and without pre-existing pulmonary disease and adjusted for working capacity (W) so that patients at high risk of dying after thoracoabdominal resection could easily be identified. Any patient with a history of pulmonary disease and a working capacity of less than 80 W whatever their age should be advised capacity thoracoabdominal resection, whereas in those without a history of pulmonary disease and a working capacity of more than 80 W, a good recovery may be anticipated. The cut off point for working capacity seems to be 80 W. Conclusion: With simple clinical guidelines it is possible to draw risk profiles for patients about to undergo thoracoabdominal resections For carcinoma of the oesophagus or oesophagogastric junction.