OBJECTIVE Focal bronchioloalveolar cell carcinoma (BAC) has been reported as often being negative on 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG-PET) scans, but no studies have examined the FDG-PET findings of both the focal and multifocal forms of the disease. The purpose of this study was to examine the sensitivity of PET in detecting both forms of BAC. METHODS A retrospective review of our tumor registry revealed 15 patients who had pathologically proved BAC and who had undergone FDG-PET imaging. FDG-PET scans were interpreted as positive if the tumor demonstrated activity that was greater than the mediastinal blood pool. RESULTS Eight patients had focal BAC, and seven patients had multifocal disease. Nine of the 15 patients (60%) had a positive PET scan, and of these, six (67%) had multifocal disease. Six of the 15 patients (40%) had negative PET scans, and of these, five patients (83%) had the solitary form of disease. The sensitivity for focal tumors was 38%, and the sensitivity for the multifocal form was 86%. CONCLUSIONS Our data confirm previous reports describing a high percentage of false negative PET scans in the setting of focal BAC. However, in the presence of multifocal disease, FDG-PET seems to be highly sensitive.