How to deal with solitary pulmonary nodules (SPN) which are incidentally detected by computed tomography (CT) is an increasingly important task in the era of modern multislice CT. This paper reviews the morphological and functional characteristics and their value for discrimination between benign and malignant SPNs. In particular, the importance of nodule size, growth rate, margin morphology, density, calcifications or fatty components within the nodules, the significance of cavitations or aerobronchograms, enhancement patterns at dynamic contrast-enhanced CT and findings on positron emission tomography (PET) are discussed. The Bayesian analysis to calculate the probability of malignancy is presented. Finally, flow charts demonstrate the national and international recommendations for nodule management.