The outcome of one hundred exploratory thoracotomies for lung cancer (9.1% of operations) was studied. There were 4 postoperative deaths. After the operation, 6 patients did not receive any further treatment, 62 received radiotherapy, 25 received a combination of radiotherapy and chemotherapy and 3 received chemotherapy. The disease-free interval was very short with development of metastases (55 cases) and local recurrences (29 cases). The survival was also short: less than 10% at 2 years; it was significantly poorer than that observed in a group of non-operated patients with an equivalent stage of lung cancer. These findings suggest the need for stricter evaluation of operative indications.