Abstract Background: Solitary pulmonary nodule (SPN) is a com-mon radiographic finding, which is frequently detected inci-dentally. Investigation of this entity is challenging, since characteristics of benign and malignant processes may overlap in the differential diagnosis. Aim of Study: The aim of our study was to estimate the value of positron emission tomography (PET)/computerized tomography (CT) in discriminating between benign and malignant SPNs by detecting their FDG uptake using SUVmax as well as follow-up their course regrading nodule size & metabolic activity. Patients and Methods: This was a prospective study for 60 patients having SPNs detected by a previous CT and followed by PET/CT examination. Fifty two out of 60 patients gave consent for diagnostic interventional procedures for further histopathological examination. Among them, biopsy was done for nodules that progressed in size or showed progression in their PET uptake (standardized uptake value; SUVmax). Results: 36 nodules (60%) of the SPNs were benign and 24 (40%) were malignant. The mean SUVmax value for the benign nodules was 2.1±2.2 and 6.9±5.2 for the malignant lesions (p=0.001). The highest sensitivity and specificity were encountered with a 3.5 SUVmax value. Conclusion: PET/CT can be a practically useful tool in the discriminating benign from malignant SPNs giving a high diagnostic probability for malignant lesions.