The purpose of this study was to evaluate the performance of 18F-fluorodeoxyglucose (18FDG) imaging via coincidence detection emission tomography (CDET) in identifying malignant lesions in subjects exposed to asbestos. A total of 30 patients exposed to asbestos underwent 18FDG-CDET between January 2000 and June 2003. A CDET scan of the thorax and abdomen was performed 60 min after injection of 18FDG in fasting patients, and results were obtained in slices in three axes. The CDET results were compared to those from computed tomography (CT), and pleural or surgical biopsy in patients with positive 18FDG-CDET results. All primary malignant mesotheliomas accumulated 18FDG (n=6), and, in two patients, CDET findings were superior to those of CT, allowing early detection. In two cases, lung carcinomas with malignant pleural effusion were also detected. There were five false positive CDET results: three unilateral pleural thickening, one rounded atelectasis, and one benign lung nodule. All patients with pleural plaques showed no significant 18FDG uptake. Malignant diseases were detected by 18FDG-CDET imaging with a sensitivity of 89% and specificity of 71%. Coincidence detection emission tomography can identify malignant mesothelioma in selected subjects exposed to asbestos. Coincidence detection emission tomography appears to be a useful noninvasive method for the follow-up of subjects with exposure risk of asbestosis.