In oncological patients, We retrospectively evaluated 182 pulmonary nodules (121 solitary, 61 multiple; mean size = 16.5 ± 8.1 mm, mean SUVmax = 5.2 ± 5.1) in 148 oncological patients (89 males; mean age = 69.5 ± 8.4 years). Final diagnosis was established by histology or radiological follow-up. Diagnostic performance of In 182 nodules, the prevalence of malignancy was 75.8%; PET/CT provided sensitivity = 79%, specificity = 81.8%, accuracy = 79.7%, PPV = 93.1%, NPV = 55.4%; ROC analysis (SUVmax cut-off = 1.7) provided sensitivity = 85.5%, specificity = 72.7%. In 121 solitary nodules, the prevalence of malignancy was 87.6%; PET/CT provided sensitivity = 82.1%, specificity = 73.3%, accuracy = 81%, PPV = 95.6%, NPV = 36.7%; ROC analysis (SUVmax cut-off = 2) provided sensitivity = 84%, specificity = 80%. In 61 multiple nodules, the prevalence of malignancy was 52.5%; PET/CT (nodule and patient-based analysis, respectively) provided sensitivity = 68.7% and 88.9%, specificity = 86.2% and 55.6%, accuracy = 77% and 77.8%, PPV = 84.4% and 80%, NPV = 71.8% and 71.5%; ROC analysis (nodule-based, SUVmax cut-off = 1.8) provided sensitivity = 71.9%, specificity = 82.8%. Malignant nodules were prevalent in males, in solitary pattern and in upper lobes, and had significantly greater size and metabolic activity (SUVmax and TLG) than benign ones, with no differences in interval-time between previous cancer diagnosis and nodule detection, patients' age or other nodules' features (lung side, central/peripheral). When comparing solitary and multiple patterns, malignant nodules had significantly greater size and metabolic activity than benign ones in both groups. In oncological patients,