Staging of non-small lung cancer (NSCLC) uses the TNM classification and is undertaken to identify those patients who are surgical candidates, either initially or after chemo-radiotherapy, and to differentiate patients who will be treated radically from those requiring palliation and to plan radiotherapy fields. Computed tomography and magnetic resonance imaging (MRI) are used in staging and provide anatomical information but have well known limitations in differentiating reactive from malignant nodes, fibrosis from active disease and in defining the extent of invasion. MRI, with its superior soft tissue contrast provides optimal information on brachial plexus and central nervous system involvement. Functional imaging using [2-(18F)]fluorodeoxyglucose positron emission tomography is increasingly being used to provide unique information and when combined with anatomic imaging will provide better staging information for both local disease and the extent of metastases.