Computed tomography (CT) is the primary imaging modality for the diagnosis, staging, and follow-up of most thoracic cavity tumors. Fluorine-18 fluorodeoxyglucose positron emission tomography/CT has established itself as a supplementary tool to CT in lung cancer staging and in the assessment for distant metastases of many thoracic tumors. Magnetic resonance imaging is an important adjunctive imaging modality in thoracic oncologic imaging and is used as a problem-solving tool to assess for chest wall invasion, intraspinal extension, and cardiac/vascular invasion. Imaging can facilitate minimally invasive biopsy of most thoracic tumors and is vital in the pretreatment planning of radiation therapy.