Positron emission tomography (PET) appears to be an innovative method for imaging the proliferative activity of malignant tissue, in particular by means of 18F-labelled fluorodeoxyglucose (FDG). The potential role of PET scanning was investigated in a satellite centre as an adjunct to conventional methods for estimating the likelihood of pulmonary malignancy. Therefore the sensitivity of detection of lung cancer in candidates was determined prior to exploratory or therapeutic thoracotomy by FDG PET imaging. The study involved 36 patients with abnormal chest roentgenogram and suspected lung cancer who were due for thoracotomy. The PET scans were evaluated qualitatively and semiquantitatively. Pulmonary malignancy was found in 31/36 patients and 29 had a focal increase in FDG pulmonary uptake. Benign pulmonary lesions were found in 5/36 patients, three of whom had a negative PET scan. The sensitivity of detection of lung cancer by FDG PET was therefore 93.5%. Bayesian study shows that FDG PET could be the most useful method in a population with a low prevalence of lung cancer. As illustrated by our study, a simple FDG PET scanning protocol in a satellite PET centre could provide adequate clinical information and help in deciding subsequent patient management.